Replacing the alternator harness

[llamavan]

See THIS Library Article (https://www.toyotavantech.com/forum/content.php?201-Replacing-the-alternator-harness) for step-by-step instructions on replacing your van's alternator harness.

Gwen

[Omicronmike]

Very nice posting and photos. I cannot believe I never realized what the + box was until now! I want to replace the high current wires going to the ground and wires going to and from the alternator with a larger gage cable, probably 0 gauge. I plan to have a company that specializes in making large gage cables make them for me because it is very difficult to buy small quantities of welding cable and the proper connectors. Do you know the length of the wire going from the alternator to the + box? Does the other cable at the + box go to the fuse link box by the battery? Any idea of the length of that wire? I think larger gage wire for those two spots and the grounds will tweek a few more amps out of the alternator and make things a little more reliable. I also plan to replace the fuse link wire with a 200 amp fuse (enclosed in its own fuse box) of the type meant for super high powered amplifiers. They cost about $20 for the fuse and enclosure. The fuse is only to protect the high current wire itself which why the higher rating and the higher rating means it has a lower resistance.

[llamavan]

+ box to alternator = 23"

Stay tuned for the other section (+ box to battery). I have to deal with that SOON. :dizzy:

Do you happen to know offhand what the current gauge(s) for those positive and negative wires are?

Gwen

[Omicronmike]

Yes, the wire is 4 gage which is typical. I know the cable going from the frame under the battery to the engine ground is 24" I admit I am still trying to figure out the best place to put the new fuse block to replace the old fuse link. I really do not like the idea of having it exposed to salt spray even though it has a cover. The fuse cover is not gasketed or waterproof amd it is far too big to put in the battery compartment

[llamavan]

Thanks for the wire gauge info! Because I'm not in a position to completely upgrade that circuit, I'm sticking to stock for now ... and because I'm really suspicious that I'm going to be rebuilding that positive wire, knowing the gauge and getting wire in advance is going to save me a bunch of time.

My measurements of the stock ground wire are 10" from battery terminal to frame and 27" from frame to engine block (just had to replace one of those — different van — with a good wire from a parts van; the original broke clean off at the terminal on the frame).

Of all the compromises necessary to make the vans what they are, the battery location is my least favorite (yep, even trumps the P/S pump location over the alternator). Anything in that area is already far too exposed for my tastes. Let us know what you come up with for that new fuse box.

Gwen

[Omicronmike]

One of my other reasons for upgrading the wire quality is because my remote start will not work with the AC on because the voltage drops too much under this condition. The van starts perfectly for cold weather to allow preheating in the winter, but cannot precool during hot weather. With the AC on and power routed through a remote start relay the voltage drops so low the starter does not even click. I have to admit i really love the keyless entry and remote start during the winter when it does work. Mike

[llamavan]

Positive wire from battery to starter = 56" (4 ga)

+ box to the first (1.25) fusible link (NOT the "infamous" 2.0 fusible link that lives in the plastic box next to the battery and is vulnerable to corrosion) works its way there through the wrapped wiring harness; any replacement will have to be run outside that, and is dependent on the routing you chose to use. It's 8 gauge wire.

Wish I could also say that one of those wires solved my van's problem. Nope. :dizzy:

Gwen

[Omicronmike]

Thanks for the additional info. I will be replacing that wire with a heavier gage someday soon, I hope. I just found a spool of left over 4 gage wire in my shop I can use, but I want to use heavier wire yet where there is now 4 gage. What was the problem you wre trying to fix in the first place? I don't think you mentioned it in this thread. Mike

[llamavan]

No, I didn't mention, mostly because I'm only now just getting back to it (and I'd like to say that's because other vans have been fixed, but it's actually because I'm waiting on parts and for PJvan to kindly vacate the carport and jackstands, so my choices of van jobs to undertake right now are somewhat limited).

Skyler is cooking alternators. Broiled, baked, fricasseed ... he's gotten WAY too good at it; he can now do this just getting down the driveway to the gate. Hot alternator implies (to me) WAY too much resistance in the wiring, but maybe I'm missing something (quite likely — electricity and I get along best when we avoid each other), so I'm open to suggestions! Skyler also blackens his positive battery terminal. I disapprove. :nono: I'm going to try a different battery in case the positive post is guilty (probably should have done that earlier; it's over 5 years old anyway).

Even though I see no evidence of problems in any of the wiring between alternator and battery, and I can't document any increased resistance in any of it, I'm going to just finish replacing the whole sheebang before possibly sacrificing my last spare alternator to Skyler's new bad habit. :wall: I told him if he eats that one, he's gonna go visit my pal Curt's auto electric shop and he's gonna stay there until he behaves.

Gwen

[Omicronmike]

Gwen,

Actually it is the opposite: if the alternator is ALWAYS hot that means there is too much of a load on it or something approaching a short circuit, but not quite. Bad wiring, if it has too much resistance, will get hot where there is too much resistance. I doubt very much if the problem is from bad wiring from your description. I assume no fuses have been blown. Yes, the battery could have a problem and drawing far too much current causing the alternator to become toast. Best way to figure out the answer is to become intimate with a digital voltmeter... What is the battery voltage when the van is not running (should be 12.5 volts or higher)? What is the voltage when the van is running (at the battery posts, should be about 14 volts)? What is the voltage at the battery with the ground wire disconnected ((should be about 12.6 volts or so)? I also recommend making sure the positive wires at the positive battery post cannot touch the chassis if the battery moves, like when making a fast turn. Mine did and the electrical system had a heart attack every time I made a fast turn. I love making fast turns in the van... Turning the connector on the post a few degrees fixed that. I strongly suspect a bad battery, however. The voltmeter can shed lots of light on what really is going on. Is it legal to say here that Harbor Frieght has been having them on sale? I got a couple meters for only $1.99!!! and they are decent.

Allergic to meters? A hydrometer will work just as well and costs about $5. A hydrometer measures the specific gravity of the electrolyte in the battery. Doesn't work if the battery is completely sealed. A fully charged battery in good shape will read above 1.2 for EACH cell. If only one cell is noticeably below the others then that is your problem. A low number (compared to the other cells) is a very reliable indication of a problem with that cell like a short. Shorts between the lead plates in older batteries is very common. The lead plates shed metal over time and build up on the bottom or create a short between the plates. When this happens you have a bad battery. Sometimes this problem can be fixed with a high powered battery charger that literally can blow up the short, but the such batteries are already on life support and ready to be replaced. I used to build lead acid batteries for experimental electric cars back in the '70s.

[llamavan]

Well, the battery was long gone by the time I read your post; new one is sitting in the carport waiting to go in this afternoon. I'm sure it was depleted below normal level anyway since it had started Skyler multiple times without being charged.

I actually LOVE multimeters, but I don't begin to use them effectively for a couple of reasons. One is that anything I ever do with electricity is not repeatable — I was the kid who couldn't get two wires and a good battery to reliably light a bulb back in whatever grade that was. So I've resigned myself to having to do everything a zillion times and trying to decide which readings are representative of reality (yes, an assortment of clips helps immensely, but those aren't always possible). The other is that the durned thing is in Greek (admit it, there's at least one Greek letter on every meter! :yes:). Besides the meter itself not being self-explanatory, any instructional material I've found defines unfamiliar terms and then promptly uses them to convey unfamiliar concepts. Kinda like med-speak goes right over most peoples' heads even after it's explained to them because the meanings haven't had adequate time to sink in. So I've gone about teaching myself only a few basic functions by trial and error, and then using logic to test stuff. Works great with circuit boards and a functioning example; I used to be able to shame techs with years of schooling. Not so easy with vans, since even side-by-side there's a lot of traipsing and maneuvering and keeping doors from whacking bodies and sometimes getting identical (or any) access to a tight spot in TWO vans takes more time than I have available.

Anyway ... an update after this afternoon's session with Skyler ... your post gives me hope!

BTW, as another fan of fast van maneuvers, I'm definitely in favor of battery tie-downs.

Gwen

[llamavan]

Update:

First, I managed not to digest that there are TWO fusible links in the wiring running between plus box and battery terminal. The first section of wire (leaving the plus box) is 8 gauge, not 12 gauge (original post has been edited to correct the previous misinformation :redface:). The wire later reduces to 12 gauge.

Second, it WAS the old battery frying the alternators (spendy lesson :dizzy:). I did replace one ring terminal (at the plus box) because the outside of it was corroding (interior wire was just fine; I cleaned it up anyway before crimping on the new 8 ga ring terminal), but decided not to replace anything else based on Omicronmike's information above. With a new battery, Skylervan is back on the road, my wallet is about to be two-alternator-rebuilds lighter, and next time I have an alternator croak, I'll be checking the battery per the above instructions as part of the replacement procedure.

I also bought a battery monitor that plugs into the cigarette lighter (http://www.equus.com/Product/Detail/9D1F54B4-F1D3-4C67-827E-91FE755F3483) (this one was recommended by somebody-or-other on TVP); I actually paid less on amazon.com and there are probably other inexpensive sources as well. I don't know how the accuracy stacks up against testing the battery directly with a meter, but it bypasses my own "non-repeatable results" handicap, and I can see it will be advantageous for "casual" battery monitoring when driving and especially when traveling (with "stuff" packed in the van making battery access less convenient).

Gwen

[JPERL]

Wire Harness NLA just tried to order

[timsrv]

That sucks. A few weeks ago there was a guy on TVP trying to sell a new harness for $25 in the parts section. I wanted it & would have purchased but he didn't give any contact info (when we started TVT I lost my TVP PM privileges & last time I tried to post it said I didn't have permission) :?: Tim

Here's the post: http://www.toyotavanpeople.com/forum/viewtopic.php?f=24&t=10638

[sgtncharge]

​
BTW, as another fan of fast van maneuvers, I'm definitely in favor of battery tie-downs.

Gwen
Just curious... Ever try doing the J-turn :silvervan:in a van?

[filterway]

does anyone know the type of connector (type, number, etc..)that plug into the alternator? not the postitve wire with the red plastic cap but the other containing 4 wires. The entire alternator harness is not available but the toyota dealer told me he can find me the exact connector that plugs into the alternator.

Maybe some could take a close picture of it and show me on the forum?

[EdCrono]

I just wanted to let know that the female end of the harness that plugs into our Van's alternator is the same as the ones in the '91 Corolla model, which I believe is the same for the Corolla's that have that same body style.

The 3 wires from the harness from the Corolla are the same as in the Toyota Van ('84 model in my case). Maybe someone can save some money like I did in the yard by conecting that end of the harness to another good end. I didn' take the whole harness out from the corolla, since it was attached to a whole bunch of other wires and I didn't want to follow it, so maybe the other end of the harness fits into the Van also.

My problem was that the wires going into the harnes's female end that plugs into the alternator of my Van were barely hanging to the plug with no wire slack for reattachment. Hope it helps!

[chrismael]

First. I've gleaned tons of info off this site and cannot say thank you all enough, especially Tim and Gwen.

That being said, I've hit a little bump in the road. While replacing hoses and repairing sensors I drizzled a little too much ATF on the Alternator. I thought I had it clean enough, but apparently I didn't. I pulled the old one and bought a new one and tried to install it today.

The problem is... The plug on my harness is 28mm (male) and the receiver on the replacement alternator is 26mm(female).

Unfortunately, the old alternator is long gone already and I'm trying to decide whether to order another alternator which looks a little bigger (Denso) from napa or if the harness on my van is not OEM and I need to replace it too. My van is 25 years old this month!

After my last go around with alternators (3 miss diagnosed bench tests) on my Honda I thought I was pretty thorough watching over this transaction, but the tester's pigtail must have fit into both alternators, because we checked new and old.... lesson learned.

Here's the model I'm thinking about getting... http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Alternator-Remfd-Standard-70-Amp/_/R-RSE2138592_0280386462

I think I could be missing something simple...

Thanks for any comments, Witty comments will be rewarded by a photo of the PBR ATF fluid guard I "fabbed" up and had mounted on the new alternator.

[timsrv]

If the sockets on both alternators look the same & have the same configuration, then the connector should interchange. Are you sure it's clocked correctly? I guess it's possible there's similar looking sockets/plugs that don't interchange, but I'm not aware of any. If this is the case, then it sounds as if they gave you the wrong alternator. If you give me a brand name and part number I'll cross reference it for you.

As you may have read from my previous posts, a new Denso alternator or an alternator rebuilt by Denso will likely outlast most (if not all) of the other rebuilds out there. So getting one of these isn't a bad plan. If you get 2 different alternators from 2 different sources and find the same problem on both, then it's safe to say it's a harness issue. That being said, if necessity dictates, you can always cut that connector off the harness and plug the wires into their spots using standard spade connectors. The harness connector is only there to make the connection easy and to make sure each wire goes to the correct terminal. If you go this route, you will want to be careful not to mix up wire locations.

The only other thing I can think of is the alternator wire harness has 2 of these round plugs (one on each end of the harness). One is a female and the other is male. Make sure you're trying to plug the correct one into the alternator (although I can't imagine why the other end would be disconnected). Tim

[TheMAN]

According to Toyota's reman guide, there's 3 different alternators used in these vans, depending on manufacture date... you can always buy one from toyota and be done with it... not cheap though... it's $173 + $30 core charge
https://www.toyotapartsandservice.com/remanguide.pdf

[llamavan]

Actually, there have been three different alternator HARNESSES for the vans: 1984, 1985, and 1986-89. All are now NLA. The differences in the harnesses have nothing to do with the connector to the alternator itself, but rather other connectors included in the harness. 1984 has no oil level sensor wire because there's no oil level sensor. 1985 has oil level sensor wiring connectors that only mate with the 1985 (3Y) oil level sensor AND the corresponding oil level sensor wire in the 1985 chassis wiring harness. The function of the wire is identical to the 1986-1989 oil level sensor wire, but the connectors won't allow the harnesses to interchange without splicing in the appropriate connectors (guess how I learned :dizzy:).

The alternators themselves are totally interchangeable and the same for all years despite part number supersessions.

I'd get a Denso (or rebuilt Denso) alternator. Even if for some bizarre reason the harness on your van has been molested and has a nonstandard connector, a spare alternator is always a good thing to have on hand.

Gwen

[timsrv]

According to Toyota's reman guide, there's 3 different alternators used in these vans, depending on manufacture date....


This is true, however all 3 of these alternators are 100% interchangeable. There are slight internal changes. The earlier ones are rated at 60A and the later ones are rated at 70A. Tim

PS: Thanks for sharing that guide with us :)

[timsrv]

www.rockauto.com has these for a much more reasonable price than Toyota. The only difference is you won't get the box that says "Toyota"

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/electrical/Densoalternatorrockauto_zps73c84227.jpg

[chrismael]

SOLVED!

Of course the root cause of the problem is between my ears. When removing the old alternator, my helper must have been a little hard on the connectors. The plastic came off the alternator and stayed in the quick connect. I assumed that if had been properly disconnected :wall: and repeatedly :wall:tried to force the new connector on top of the old one. Better lighting for now on!!! Thanks for the help All, I am sure to be back as the project continues. But at least now I'll be up and running!
-chris

[inthar]

okay so this looks like the fault of accumulated psf. thought I had fixed the leak with a new hose but i guess there was still a small drip.

anyone got one of these they could sell me or any crafty ideas.
Thanks, Niko.


http://i1304.photobucket.com/albums/s528/intharbuddy/P2075132_zps10d47fac.jpg (http://s1304.photobucket.com/user/intharbuddy/media/P2075132_zps10d47fac.jpg.html)

http://i1304.photobucket.com/albums/s528/intharbuddy/P2075133_zps14d7aa16.jpg (http://s1304.photobucket.com/user/intharbuddy/media/P2075133_zps14d7aa16.jpg.html)

[timsrv]

The harness for the van has been discontinued, but there are lots and lots of similar harnesses on other models in the salvage yards. You could chop that end off of one then solder/shrink tube it to your existing harness. For an emergency repair you could do what I did (below). The spades inside the alternator are standard so you can make each connection individually (just don't mix them up). Tim

http://i8.photobucket.com/albums/a23/timsrv/IMG_6605.jpg

[sgtncharge]

I replaced the alternator pigtail connector on my 89' 2WD van with one I found at the salvage yard that was on a 88' Camry. It fit just fine but the wire gauge was smaller and the wires were different color. I may have spliced it on incorrectly. I want to take the pigtail connector off and use three clips instead but need a diagram that shows which wire connects to where. Can somebody please help?

[timsrv]

Here's a diagram I marked up with the wire colors used on van harnesses:

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/electrical/densoaltwirelocations_zpse28810a5.jpg

[sgtncharge]

Wow! That's perfect. Thank you so much.

[Ncbcvan]

I cannot find the 4y or 3y harnesses anywhere. The post is awesome however, and very helpful. So goi are saying. Can use a 91 Corolla harness, which might be eAsier to find and fix the problem. My harness melted at the end that it's info the alternator so I. New one.

[timsrv]

Yeah, I heard they were all gone. I always had one or two new ones rat-holed away, but I just used my last one a couple weeks ago. I guess the future will require repairing and/or modifying other harnesses to fit. There are lots of cars out there that use the same connectors, so modifying shouldn't be too hard. The round plug with 3 wires is probably the only part you need, and you get those on eBay: http://www.ebay.com/itm/Alternator-Repair-Plug-Connector-FITS-Nipondenso-Toyota-Honda-Lexus-Chevrolet/171404912337?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%2 6asc%3D35851%26meid%3Df0d0ab5862c8405bb81a9bf48695 3657%26pid%3D100011%26rk%3D6%26rkt%3D10%26sd%3D161 823358577. Oh the joys of owning old & obsolete vehicles :wnk:. Tim

[Ncbcvan]

Wire Harness NLA just tried to order
w
As not able to find a wiring harness either. What did you do? What do you suggest?

[Ncbcvan]

Yeah, I heard they were all gone. I always had one or two new ones rat-holed away, but I just used my last one a couple weeks ago. I guess the future will require repairing and/or modifying other harnesses to fit. There are lots of cars out there that use the same connectors, so modifying shouldn't be too hard. Oh the joys of owning old & obsolete vehicles :wnk:. Tim

would you happen to know what cArs, I should start sourcing, use the same connectors by any chance? Thanks, jay

[timsrv]

Lots of cars use variations of our Denso alternators. Many are the exact same alternator, just slightly different mounts. Even other brands like Honda and some Chevy's used them. I would stick to Toyota though (less chance of mismatch). Most Toyotas from the same era will have the same alternator connections. Tim

[JPERL]

I had my auto electric shop fabricate one using my old one as a template

[Jbbishop2]

Can you folks tell me which color wire goes to which blade of the alternator end of the harness? When I pulled my alternator out, the wires came out of the corroded plastic plug.
1599
This is the other end of the harness:
1598
I don't mind duplicating the "hack job" Tim showed in an old thread, or more likely just embedding the connectors into the plug shell in the right places and cementing them in with RTV or Plast-Aid, but I don't know how to tell what goes where.

Thanks,
John

[timsrv]

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/electrical/alt_diagram_zps907cbf7d.jpg

[Jbbishop2]

Great! This is exactly what I needed; thanks, Tim.

[Ncbcvan]

you will not believe it, but i found the exact make, model, and year of my lil van in a junkyard 40 minutes from durham nc. there are not a lot these vans in this part of the country.


the vanwagon angels were shinning down on me , as the alt wiring harness was there and the engine was clean, so the dismantling process was not that hard or messy. it only had 150,000 miles on it, belonged to one owner, who treated it kindly, and it had been parked for several years before being sold to the junk man.


i am considering buying the van for parts. oh did i mention it is a five speed as well. amazing luck.


i should play the lottery today. it seems that most of toyovan enthusiast i read on the forums have one, if not two, three, four or five vans in tow at any given time just to keep one on the road. lol.


i bought my 1984 off the streets of northeast portland oregon in 1999 and have driven it coast to coast several times, and up and down the I5 corridor enroute to rivers, mountains, trails, and discos since putting my first of four alternators in it in 2001, thank you autozone for lifetime warranties, and it has not failed me yet. i must fix the power steering.pump soon.


by the way this last time the alternator caught on fire when i started it. right at the female end were the alt wire harness fits in. the harness melted. ever heard of that happening?


had to leave it in florida for a few months while i.looked for this part. flying down there today to attempt to repair and drive it back up to north carolina. any thoughts on causes or cautions with respect to fire?


thanks.

[Jbbishop2]

I don't think I'll monkey around with trying to fix the old harness connector shell; a new replacement on eBay is only $11.25:
http://www.ebay.com/itm/151303054390?item=151303054390
1600

[Jbbishop2]

The eBay connector came with short leads installed, but I pulled them out and slipped in the spade connectors already on the alternator harness wires:
1655

The connectors on the short leads each had a tang that clipped them into the shell, but the ones on the harness did not, so to keep them from backing out when the plug was inserted, I potted them in with RTV:
1656

When the harness is installed, at idle the battery is charging and the Christmas lights are still gone:
1657

[mons]

Hi! I have been looking up how to connect the alternator to the harness for days now. I just replaced the alternator in my van and when we were disconnecting the old one realized that the plug was missing. What I have instead is the wire in the uploaded photo, which is obviously connected to the wiring harness but is definitely not long enough to reach the alternator. It's pretty clean and the area around the terminals on my old alternator is pretty clean so I can tell there was something connecting the two parts. I looked all over to find what could have been connecting that part to the alternator, and ended up ordering this:
http://www.ebay.com/itm/NEW-NIPPONDENSO-ALTERNATOR-REPAIR-PLUG-HARNESS-CONNECTOR-TOYOTA-HONDA-LEXUS-NEW-/151303054390?pt=Motors_Car_Truck_Parts_Accessories&hash=item233a5d6436&vxp=mtr

So, this connects to the alternator but I have no idea what to do with the three wires. I have seen some instructions on which wires go where, but how do I connect them with that weird harness plug that is already in my van?

[djshimon]

https://www.toyotavantech.com/forum/showthread.php?91-Replacing-the-alternator-harness&p=10734&viewfull=1#post10734
Timsrv, Post 28. That's which color wires go to it.
As for electrical connectors-I would get one from the junk yard and solder/heat shrink a used one on. Or if you can't find that male harness for that connector you could use three sets of spade connectors and make your own "harness".

[ratatouille]

This thread seemed like the best place to post this. I'd like to fab together a new alternator harness. I don't know jack about wiring/electricity etc., but I watched a ton of McGyver episodes growing up so I bet I could figure it out with a little help. ha! Thanks..

Here's what mine looked like as I just took it out and stripped the decaying flaking wrapper to old harness.
1734
alternator connection on left. "+ box" on right. I did not unwrap and remove oil level sensor wire usually bundled with the harness. It looked fine and is working.

I'm stuck at what kind and size/gage wires to get??? I may save a little and use the same terminals, but only if I can open them up clean and it works out. The black clips seem to still be in good shape...

1729

1730
Alternator end of harness.


1731

1732
Wires leading to "+ box". Looks like one is slightly larger ?

1735
Fried "+ box".

I hunted high and low for something to replace + box. I had no luck locally. Anyone have any suggestions ?

If not, I found a few a few types of junction leads online. I may order something like below. Does it matter what kind of junction to get?

1733


Thank you for any help! Respec!

[timsrv]

As far as I know the + box is still available through Toyota. I ordered a couple last year and there was no problem getting them. They are Toyota part #82671-28020 & go for around $15 each. You can get the 3-wire Denso plug on eBay: http://www.ebay.com/itm/Alternator-Repair-Plug-Connector-FITS-Nipondenso-Toyota-Honda-Lexus-Chevrolet/171404912337?_trksid=p2047675.c100011.m1850&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%2 6asc%3D35851%26meid%3Df0d0ab5862c8405bb81a9bf48695 3657%26pid%3D100011%26rk%3D6%26rkt%3D10%26sd%3D161 823358577. It comes with enough wire to splice into. Butt connectors would work, but for this location I would recommend solder & shrink tube.

I have the special crimpers for putting eyes on the bigger wire & I could easily fabricate these. If there's enough interest I could probably make up a few and sell to anybody who wants one. Toyota was selling these for around $65 before they dried up...........anyone willing to pay $50 each for ones made by me? If 10 or more people want one I'll make up a batch. Tim

[pinkgrips236]

I picked up one of these (http://www.ebay.com/itm/NEW-NIPPONDENSO-ALTERNATOR-REPAIR-PLUG-HARNESS-CONNECTOR-TOYOTA-HONDA-LEXUS-NEW-/151303054390?pt=Motors_Car_Truck_Parts_Accessories&hash=item233a5d6436&vxp=mtr) a while ago while doing a harness repair.

The plug fits right into the alternator, and I just cut out the plug end you have pictured and replaced it with a few different good quality quick connects.

Works great so far!

[ratatouille]

I have a trusted source at toyota that digs for me when parts are needed. No luck on the box. He even dug pretty deep to see if he could find a harness laying around somewhere. No luck. Not to say box is not out there, he just couldn't get one for me.:?:

I'm on a tight budget so I've got to try and build my own using what I can from old harness. If I had the cash Tim, I'd take 2 or 3. Thanks for being willing. Tim I bet you'd make some good money if you had your own online store going.

[timsrv]

Yeah, I'm not so sure I'd make money unless I had big buying power. I checked into some of the materials and found some to be quite expensive. The high temp braided loom that covers the harness goes for almost $4 per foot! (and that's if I buy 50 or more ft at a time). The Denso plug goes for around $12, then there's the other Denso style plug that goes to the van harness (didn't look that one up yet) the wire, terminals, and the boot. Not including labor, to make a reasonable copy (without the oil level sensor part) would likely cost me $40+ each. After getting that far I decided it's not worth my time. Next time I need one I may make a few and put them for sale here (in the classifieds), but that won't be anytime soon. Tim

[Burntboot]

I ordered the 82671-28020 about a month ago, sitting on my desk as we speak, just waiting for install.
Now I WISH I had only paid $15 for it, probably best if we don't talk about that aspect, at all.
I do tend to lose it whenever we start talking about Cdn parts pricing.

Your guy should be able to get one.
BB

[timsrv]

I had no problems, but it's been almost a year since I got mine. More & more I find things are here today & gone tomorrow. Canada does a lot of things better than the US, but they suck on pricing parts. At lease we do better on that here in the US............IMO we're paying about 3X too much. Thanks for sharing as it takes the sting out knowing that you Canucks are paying 8X too much :lol:. Tim

[trestlehed]

Hey Tim,

I thought there was an older thread where you had found an outfit that specialized in rebuilding wiring harnesses.
Is that the case or am I thinking of something else?

[timsrv]

There's a member here "wirewrkr" that has a business rebuilding motorcycle wire harnesses. He had posted a link to his website & this type thing looked to be right up his alley. He hasn't been around for a while though. I just checked his website and see it's gone now too. Maybe that's the thread you're thinking of? Anyhow, I hope he's okay & still has a van. Tim

[ratatouille]

I love these forums..but I sure wish I didn't have to spend so much time here. I've dug through so many posts and I just can't seem to nail what's going on with my van.

I'd like to post the nice pictures I took of my harness build. But I'm not so sure I did things correctly.

Been dealing with electrical issues for a little while now. (hope this is ok to ask this here in this thread...) I thought it was alternator issue to begin with. I've been through 3..or 4 now. In past 3 months or so. No the steering pump is not leaking. Alternators have been clean. The last one the shop said it was faulty and they told me they would rebuild. I believe it is a Denso. Put returned alternator back in.

In the mean time, after doing research here, realized my van did not have FL 2.0L OR FL 0.5G ! Weird that I actually drove van for about a year with no issues until now. SO, I replaced FL 1.25B, and added the FL 0.5G and FL 2.0. I figured I might as well build new harness as well. So I fabbed together new harness and also put in new junction box to replace burned "+ box"...got everything buttoned up. Van started and ran nicely, no xmas lights. Battery terminal initially showed 13.8 v at start up. Drove for about an hour then things went dim and barely made it home. I took a small video I can post later, showing all the lights flickering everywhere as I idled and rev'd the engine. Van sat overnight. In the morning van won't start now.

I'm stumped. Could it be that i did not build harness proper? Any help is much appreciated. I'm about to set everything on fire at this point :pissed:...

[Burntboot]

My main issue was with on-going intermittent no cranking but also had issues with charging circuit.
I too was missing the 2.0 and .5 FL's.
I went through 2x FL1.25B and while doing some body work had occasion to pull the main harness.
I started at the FL1.25B and worked backwards then I found a failed factory splice which caused me to look further.
In the end I cut out a zillion factory splices, replaced about 5 miles of wire (essentially everything in the engine bay area) I found issues with the wiring for things ranging from start and charging circuits to engine management to lighting to you name it.

The wiring for FL1.25B disappears into the main harness behind the battery, along the frame rail and up into the engine bay. There are several wires that splice off all the wires to that FL (alt, starter, 60AMP fuse, +ve power post………).
While I am not yet able to claim that I have fixed my issues (it came off the road for a 2 week repair, 7 months ago and is still apart :no: )
I am truly expecting things to be a WHOLE lot better.
Silver wires (copper depleted) are not very conductive, nor are green splices.
There are pics in the other thread ("xmas lights continued", IIRC)

I would go back over the repairs you've already done, just to make sure something in the alternator harness didn't come apart but if that doesn't show any smoking guns, also check to make sure the "good" alternator isn't to blame.
But if all those check out fine, I would then dig further into the main harness.
BB

PS - I just looked at your pictures again and realized that the wiring that can be seen looked very similar to all that I have replaced.
What I found was key to the whole procedure was that any wire that felt stiff or looked "dirty" (at first I just thought it was dirt) turned out to be damaged wiring.
After a while I stopped cutting open insulation and just replaced anything that was stiff, occasionally I would double check what I had just cut-out, but even stopped that after a few times of confirming my suspicions.
I also found that if one part of a circuit had issues, I was almost guaranteed I would find more further downstream, hence the rec to dig further into the harness.

[ratatouille]

Thanks burnt. I saw your other thread and I don't think I'm willing to do that kind of work. Would rather push it off Big Sur and let it sink... I'm hoping I find a mistake in my harness build or my fusible link work. Or hoping the alternator my shop "fixed" is not actually fixed.

Jumped the van this afternoon and it runs without being on jumper cables. Volts at battery are reading between 9 and 10 volts. Battery reading 11.5 or so when not running. Anything else anyone knows that I can test while running, or not running to rule out, or narrow down issue?

Anyone have a photo of the upper connection on the alternator harness where wires connect?? I have a feeling I might have not clicked the wires into the connector in their proper location...

I'll post pictures this evening to see what you all think...

[ratatouille]

Ok. I may have found my issue. I used a life line and phoned a friend. Got a picture of the upper alternator connection. I suppose I could have just looked at the male end of upper connection in van to realize my mistake...:doh: doh! When I built the harness, I clicked the wires into the plastic clip wrong. I swapped the "IG" Terminal and the "B" Terminal. "IG" Terminal is the ignition switch to turn the regulator on. And the "B" Terminal is the Grounds and warning lamp terminal.

Not sure if this is going to solve all my problems. But I've fixed the harness and proceeding.

[adamh]

i suffered an age old symptom of red battery and orange engine check lights flicking on/off on the dash, engine stuttering thought it was a bad earth or something, first i checked all the fuses under the dash and in the engine bay, found none blown but the red battery light and orange cel still show on dash, usually means dead battery or alternator. i had recently disconnected my alternator so i thought i would look and see if i made good connection with the plug. it was plugged in tight but I pulled back the heat proof sheathing and found this:

er http://i295.photobucket.com/albums/mm134/hutchisonphotos/tonto/SANY0045_zpsmzxq4mxp.jpg (http://s295.photobucket.com/user/hutchisonphotos/media/tonto/SANY0045_zpsmzxq4mxp.jpg.html)

i guess over the years of people working around the area the cable got frayed, as luck would have it it frayed right next to the plug so i thought i was screwed, and would have to find one at a junk yard with long cable.

on closer investigation of the oem plug i removed the rubber dust cap on the back and found using a small screwdriver you can actually release the spade pins from the plug quite easily, they have a little spring latch (barb) where the green arrow shows, just push it in with a tiny scredriver from the open end of the plug and the pins pop out with a little tug.

http://i295.photobucket.com/albums/mm134/hutchisonphotos/tonto/Untitled_zpslvdy0n83.jpg (http://s295.photobucket.com/user/hutchisonphotos/media/tonto/Untitled_zpslvdy0n83.jpg.html)

bad luck went to good luck... my local parts store had a supply of 2/3/4 pin connector plugs and they use exactly the same 1/4" latched style pins.. so i stripped the pins from the plug, attached some longer wire and they clicked right into the oem alternator plug. suprising!
put the rubber dust cap back, just soldered and shrink wrapped the new wire connections and taped after, no trip to the junk yard searching for old looms and plugs. :thmbup:

http://i295.photobucket.com/albums/mm134/hutchisonphotos/tonto/Untitled2_zpsrs5egf6e.jpg (http://s295.photobucket.com/user/hutchisonphotos/media/tonto/Untitled2_zpsrs5egf6e.jpg.html)

http://i295.photobucket.com/albums/mm134/hutchisonphotos/tonto/SANY0002_zpsqpyc33s6.jpg (http://s295.photobucket.com/user/hutchisonphotos/media/tonto/SANY0002_zpsqpyc33s6.jpg.html)

(http://s295.photobucket.com/user/hutchisonphotos/media/tonto/SANY0049_zpszmi9kjfw.jpg.html)

[Jbbishop2]

Nice work, Adam! Thanks for the write-up and photos.

[mahleek87]

Hi Yall,

Had a rough night tonight...

1st, I noticed the christmas lights on the dash of my 89 van. Before I used to just play around with the positive wire that goes to the alternator and snug it in more and it would go away. It is broken and doesnt clip in, thats probably due to someone yanking it out in the past. But anywho, this time I tried to push it in when that happened and the lights were still on. I had a friend look at it and he saw that the positive wire sparked pretty bad when he touched it and said its grounding out. He said that wire needs to be fixed and thats my problem... Has anyone ever repaired this positive wire? The plastic positive post on the engine bay looked a little melted. I doubt my alternator has gone bad because the ps pump is not leaking...

To top the night off I had the van towed back to my flower shop and I had a couch inside the van. While the van was being towed i guess the couch moved around and It busted my rear left window while it was being towed and ofcourse the tow company explained to me that they are not liable for that.

[brentlehr]

I thought Tim had a nice write up about alternator harness issues but can't find it. Maybe he'll chime in.

I'd focus on repairing the loose connection for sure. If it's moving around and sparking while you're driving you might end up with a burnt up van.

Check that your alternator is charging.... voltmeter on the battery should read over 13.5 volts while running.

[nikifix]

my positive connection failed and melted the little black terminal box.............I cut the two eyes off the wires ,stripped about an inch of wire jacket off and used a splice cap/marrette .....a big blue one and packed a little blob of silicone in the end......ask an electrician for one maybe......pre twist the wires together first before twisting on the cap

[Burntboot]

Maretts have absolutely NO place in a vehicle, especially in a place that carries that kind of current.
The pos. post is still available from Toyota and isn't crazy expensive.
It WILL solve all your problems and save BBQ'ing your butt.

[nikifix]

BB the splice I did with a marette has been good for 5 years ....no problem.....I used a little anti oxidant goo also for good measure[nolox]...marettes don't carry current ,just hold the wire......I rather rely on a marrette than a pair of crimped stakon eyes......I thought about using a split bolt but didn't like the idea of the electrical tape melting in the heat.

[Burntboot]

Hey Nik
I was always taught that Maretts don't like vibrations and can't be trusted to hold things secure.
I am also not a fan of crimps for most applications (attaching fusible links would be the exception) but prefer to solder and shrink.

I like to keep my positive wires well secured, and see no sense in doings things part way, but am glad it works for you.

Given that OEM parts are still available and affordable, I don't see the point in taking chances.
BB

[ratatouille]

To follow up on this..It's been a while and the DIY harness build and fusible links and work I did has held up fine. The issues I continued to have were due to aftermarket alternators. To date I think I've gone through 5 alternators. I kept having to swap out ones from Oriellys till I found one that worked longer than a few weeks. Almost each failure happened while on long trips (100+ miles) while driving for hours on end. Maybe the long heat and load on these things frys them. Ultima I think is the brand Oriellys uses. These "lifetime warranty" alternators are trash in my opinion and they don't fit right. What I ended up doing was finding an original denso/toyota alternator in a junk van with somewhat low miles and used that instead and I have the last one I bought on hand as a back up. What I'd like to do next is buy the internals for the og denso and keep that one going strong. Here's the thread timsrv outlines that- http://www.toyotavantech.com/forum/showthread.php?335-Alternator-woes&highlight=alternator

[Mtn_Van]

Here's a diagram I marked up with the wire colors used on van harnesses:

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/electrical/densoaltwirelocations_zpse28810a5.jpg

My charging wire (+box to the alternator post) is actually two 10g-ish wires with separate eye connectors to the alternator post. Can someone please confirm that this is the stock setup and not something shady from the PO? I discovered (after much popping and smoke until I unhooked the batt ground) that indeed a 2nd wire (with a missing eye connector) was partially exposing itself out of the harness sleeve. I'm frustrated I didn't catch this earlier, and am concerned that I may have fried a thing or two as a result.

[Burntboot]

Pos box should have 2 wires with ring ends.
One heavy wire coming from the battery, the 2nd heavy wire goes off to the alternator.

The factory wire is fairly light gauge and I dont remember if it was a double wire or not.
When I replaced mine I used 8g wire with soldered ends.

[Mtn_Van]

Thanks, Burntboot. Looks like mine is similar to Ratatouille's in post #44 (likely 10g and a second 12g or 14g wire). But since the repaired wire is now a tight fit and I foolishly broke the +box in the process, I'll be upgrading to an 8g this weekend.

[nikifix]

Hey Nik
I was always taught that Maretts don't like vibrations and can't be trusted to hold things secure.
I am also not a fan of crimps for most applications (attaching fusible links would be the exception) but prefer to solder and shrink.

I like to keep my positive wires well secured, and see no sense in doings things part way, but am glad it works for you.

Given that OEM parts are still available and affordable, I don't see the point in taking chances.
BB
well it is 2020 and big blue marette is still hanging in there haha

[fastcanoe]

My alternator plug had been causing me some troubles. I noticed the last time I changed the alternator that the plug/wires were on their way out. I rolled with it, but soon after started getting christmas tree lights intermittently. one time, which was on a drive from SF to SD, just over the Grapevine, the dash lights came on solid. I pulled over (in the dark) and managed to discover that if I bent the wires in a certain direction, the dash lights would turn off (completing the circuit). I ended up using two zip ties around a hose to keep those alternator wires bent towards that sweet spot. Exactly like when your cell phone charger cables starts to crap out and you have to bend the wire to make it work. This was a quick fix that ended up lasting the rest of the trip to SD, the drive back to SF, a month of puttering around town, and a drive back to SD! A few weeks after that last drive to SD is when it really started to get wonky. The sweet spot was almost nonexistent at that point.

ANYWAY, I finally got around to pulling the harness out. I replaced the plug, and soldered those new wires that came on the plug, onto the existing wires in the harness. I had to trim back a little bit to get to the section of wire that was still healthy. Shrink wrap and E tape, back in biz.

While doing this I also re-seated the + wire to the alternator. The spade that is on there, didn't sit completely on the nut of the new alternator, so I put it on upside down, which ended up making a WAAY more solid connection.

Result - brighter lights, what seems to be a little more pep in the step, and...better gas mileage?? When I got the van, the coil was bad. I can't help but to wonder if these wire issues had been an issue for quite some time leading to other electrical concerns / problems.

Anyway, I barely took any photos because my hands were all gunked up. But I'm stoked it worked out!

[potatovan]

What are the wire gauges to build a new whip from alternater to harness please?

[coreyhucks]

I m having some alternator issues right now. Want to do a thorough test of the wiring. Continuity from all the wires in the harness back to the connector. Does anyone know the points behind the connector I can test for continuity? I m particularly interested in IGN circuit on the alternator connector. I attempted to test for voltage on the ignition wiring and found none. Any suggestions would be helpful.

[LeonDaneko]

This is a really dumb qeustion but hypothetically... if the sense wire was cut off or perhaps, entirely missing... what symptoms might you have?

[timsrv]

Read the 1st post in THIS THREAD (https://www.toyotavantech.com/forum/showthread.php?136-The-fusible-link-thread), particularly the part describing the FL 0.5G fusible link. Tim

[LeonDaneko]

Sweet, I brought it into the shop and they went through 6 warranty alternators. Where might i find this sense wire?

[timsrv]

:cnfsd: Did you read the other thread? What was the charge voltage on the other alternators while they were functioning??? Is there a power steering leak getting on the alternator? Are you using a genuine Denso alternator or one of those cheap aftermarket rebuilds? I'd also recommend searching the site for the thread "alternator woes" and read. Tim

[LeonDaneko]

Some alternators out of the box were fine for a short while, then others would come out of the box with charging voltages of 15-17.8volts. The 7th one. Which is currently inside my van seems fine. But thats because after the 2nd alternator, i got fed up and brought it into a shop. When i first arrived, i told them to inspect wires behind the dash and the fusible links. After the 5th one I told them again and they did. Now it charges. But it doesnt seem like it actually knows where my battery is at in terms of charge. And I can't find the area on my van that this sense wire should be.

[timsrv]

The info you're after is well documented in those 2 threads (and others). Tim

[LeonDaneko]

i appreciate it. they've been very helpful. BUT I cannot for the life of me locate the sense wire (0.5g) fusible link. maybe that's my problem.

[timsrv]

The 1st thing you should do is unplug the round alternator connector and check voltage at the white sense wire. If you see battery voltage here the sense wire is hooked up and there's no need for further investigation. If however there is low or no voltage here, that's a problem that needs to be investigated.

Here's a picture from the fusible link thread:

http://i8.photobucket.com/albums/a23/timsrv/IMG_0168.jpg

The 0.5G fusible link is the little yellow cylinder to the right of the battery. This connects the battery + to a white wire that goes to the "S" terminal on your alternator. Even if yours is there and is hooked up, it's very possible it's corroded and/or not making good contact. Over the course of 30 something years, it's also very possible somebody broke or cut this out, but the wire should still be down there going into the harness. If you find the end of a ~14 ga white wire down there that's cut/broken, it's a good bet that's it. If you find that wire, use a meter to verify continuity from it to the alternator harness "S". Assuming you see continuity, hook it up to the Battery positive terminal via an inline fuse. Based on wire size, I'm thinking a 10 or 15 amp fuse would be appropriate. After hooking it up, use a voltmeter at the "S" terminal again to verify you fixed (should see battery voltage here). If there is still no voltage or you can't find the wire, you could always run a new one. Tim

PS: Due to age and extreme conditions, it's also possible wires in the alternator harness are compromised. Due to years of vibration and flexing it's not uncommon for the last few inches of wire going into the alternator plug to become broken and fractured inside their insulation. The worst part about this type of degradation is connectivity is often intermittent. Intermittent problems are hard to diagnose, so if you think this is a possibility you may opt to simply replace this part of the harness. Even though the OE alternator harness is NLA, as shown earlier in this thread you can still get the round plug with wires from aftermarket sources.

[MyToy]

Hey Tim:

Referring back to your message #66 in this thread you show a picture of the 3 pin connector for the alternator. Is this illustration looking at the male connector of the alternator or is it looking at the female side of the harness? I know it says "plug to alternator" but my wires colors do not match and I just wanted to be sure. A kind yes or no would be very helpful. My machine is down and I am trying to get her back on the road.

Thanks Tim

MyToy

[timsrv]

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/electrical/densoaltwirelocations_zpse28810a5.jpg

http://i8.photobucket.com/albums/a23/timsrv/TVT%20pics/electrical/alt_diagram_zps907cbf7d.jpg

That sketch is representing the alternator itself (the socket where the harness plugs in). If you're looking at the harness plug, the side that is closest to the alternator, the wires color/function would be a mirror image.

[MyToy]

Perfect! On my way back on the road!! Yippie!

[Jheinz]

So I've been dealing with intermittent christmas dash for awhile. This week I finally got around to checking it out. I had a spare alternator sitting around, so I started by taking it in to my local autozone and had it bench tested. All the checks came back green, so I decided to try installing it. After the install, I saw that my battery was not charging, although I did not have the christmas dash anymore. I decided to pull the harness, and after checking for continuity I found that 2 of the pins were no good. I ordered a replacement plug off of ebay and spliced it onto the harness. Now I'm charging but still have the christmas dash. My battery is at about 12.5 volts when the van is off and around 14v while running. It seems like my 0.5 fusible link is completely bypassed, although one end is still connected to the battery. I've also checked the charge fuse under the dash and it is not blown. Any ideas what could be causing the christmas dash? Here are my current thoughts:

- Perhaps the alternator I put in was never good, or perhaps I damaged it. I did end up shorting out the battery and blowing the 1.25 fusible link due to a stupid error on my part. I'm very much an amateur when it comes to electrical repairs haha. I've ordered another alternator from Autozone that should be here in a few days. Side note: Anybody have a good source on alternators? I know the autozone ones don't tend to last. Worst case I'll probably look into repairing one of my dead ones, or find a local repair shop.
- It could be possible that I mixed up the L and IG wires when I spliced on the new connector. Would that cause the christmas dash even though the battery is charging? Is there any way I could tell that I mixed up those two wires?
- Maybe the fact that the 0.5 fusible link is disconnected has something to do with it. But it seems like that fusible link is intended to protect the S pin, correct? I was reading voltage at the S pin on the new connector. Where is the 0.5 fusible link supposed to connect? One end is coming out of the positive battery terminal, where should the other end go?

Any help would be greatly appreciated. I'm certainly quite a novice when it comes to electrical work, and while it sucks that the van isn't drivable, this is proving to be an interesting project. Thanks to everyone in this community, I wouldn't have even known where to begin if it weren't for all the helpful information on this forum.

[Jan-Willem]

It seems like my 0.5 fusible link is completely bypassed, although one end is still connected to the battery
What do you mean exactly? there needs to be a wire, from the S(ensor) of the alternator, to the plus pole of the battery. It came with the yellow fusible link thingie near the battery. This wire should be direct, the shortest possible route from the alternator to the battery, it should not go to any other positive sources or be shared with any electrical devices on the van.
The idea is that current through a wire causes a voltage drop on that wire. So the alternator needs that wire, to measure the voltage of the battery, without any other currents influencing that measurement.
I thought I had a smart idea once, to put a relay in that circuit, to prevent a slow drain, even that was too much on the sensing circuit, and messed up the proper regulating of the alternator.

[Jheinz]

Doh! I am indeed a fool haha. It turned out that the 0.5 fusible link was in fact connected to the wire that I assume goes to the alternator, while the disconnected end was supposed to be connected to the battery. While the van is running, touching the exposed end of the fusible link to the positive battery terminal causes the christmas dash to go away. I think I'll be up and running once I splice a new ring terminal onto the end of the fusible link. I'll update later today with more info if I have any more trouble.

[Jheinz]

So now I've encountered a new problem. After correctly hooking up the 0.5 fusible link, my problems seemingly evaporated. Until last night, when I got Christmas dash while driving home at night. When I start the van, the alternator seems to be providing normal output. But after driving for only a minute, I get Christmas dash. Voltage at the battery and the plus box indicates no charge from the alternator. Interestingly, unplugging the 0.5 link causes a seemingly correct voltage of 13.8 volts. From what I've read here, without the S wire being connected the alternator will go into "full field mode" which can be dangerous. After shutting off the van for a few minutes and restating, I'm seeing the correct voltage again at idle until I drive for a minute or two. Could this be the regulator inside the alternator? I will probably try installing the replacement alternator and see if that helps. Any other thoughts on what I should check?