Christmas lights continued

Over in the fusible link thread, Tim helped me sort my issues and all was GREAT, for a week or so.
Then, I started having that odd dash flash on start-up but it always went away after a second or two, so I tried to ignore it.

Yesterday, the interior light bulb blew and this morning I am back to steady xmas lights.
I suspect the bulb didn't like having 15V coursing through it.
On the upside, the clock has been keeping PERFECT time ever since the repair (It's been AWOL for the past 2 years)

When I checked voltage (engine running) I had 12.5 at the battery, then I checked it at the pos post under the seat and found 15V, not so good.

Double checked all the repairs from the other day and that all looks good.

As the alternator harness is hard to access, I parted the upper plug to the alt harness and checked for continuity of the wiring and found that I have 65 ohms resistance on the FL 0.5G wire.
As luck would have it, while checking the "signal" wire, I accidentally contacted ground and found zero resistance.
:no:

My limited electrical knowledge tells me that this is a really bad sign.
I have visually inspected what little of the harness I can see and there are no obvious pinches or rubs but it is far from easy to tell anything for sure.

Seeing as I don't have time or desire to rip out the whole harness apart to find the breach am currently thinking that running a new wire
from the alt harness connection back to the fusible link at the battery will be my best course of action.

Don't like that plan much as I find electrical faults to be like mice, they never travel alone.
But as time is of the essence, I may have to resist my AR tendencies.

From the diagram, I can't see anything else that would be affected by running a new wire but figured I should consult the guru before doing anything potentially stupid.

Thanks in advance

BB

I know I'm not the guru you are looking for...

But..

You didn't mention checking the ground wire on the battery. Did you check it's continuity?

It may not be grounded correctly from what you mentioned. Or perhaps a loose cable somewhere..

15V at engine & 12V at the battery with the alt. in full tilt mode. I think this means there is either something creating resistance in the battery circuit to drop the voltage or a connection is loose so its not in parallel with the rest of circuit / alternator & engine.

maybe a bad ground wire on something else... ?

Someone give that man a cigar.
I am foreverly grateful for the reply.

Thought about what you said, while I had assumed all was good at the neg side I decided to take a closer look.
Turns out the PO had installed a butt crimp without shrink ( nice and green under the tape) on the little tag wire off the neg side, that coupled with the preformed neg terminal, I threw caution to the wind and replaced it all with new.

Your post also prompted me to go back and double check what I was doing and turns out, I was reading the manual wrong and the wire I was testing was NOT the sense circuit. argh.
I have had partial success as the christmas lights are now gone (yay).

My problem now is that I now have 15V at the battery, as well as everywhere else.
The fusible link seems fine, will have to dig back into the harness to find out why I am still full-fielding the alternator.
BB

Wow, glad my elementary knowledge of electricity could provide useful. & two :bluevan::bluevan: for using my username in a proper sentence that doesn't include cuss words.

You might want to give it a minute though before doing anything else... Perhaps your battery just needs a little touch-up, then the alternator will chill out.

But I think you are closer, if not already there. Unless you see some visual clues I wouldn't touch the wiring to the alt - 65 Ohms sounds pretty good.. probably equal to a couple of decent crimp jobs & a fusible link.

I was hoping the same thing, but it didn't seem to tailor down even after 1/2 hour of running time.
That said, the manual seems to think that anything up to 15.1V is within spec, seems awfully high to me, but what do I know.
Dome bulb has been replaced as it seems to be a good indicator of an overcharging condition.

The 65ohms was totally irrelevant. I wasn't even on the right wires, Doh.
Must learn to be more careful when reading those diagrams.

Thanks for saving me, from myself.
BB

That's good you found your bad ground. If you're getting too much voltage, then as you suspected, it's likely an "open" somewhere in the FL.5G circuit -or- you might have a faulty regulator inside your alternator. Tim

So, this saga didn't end with the above post, that repair only bought me a few more days.

At this point I gotta say, there is VERY good reason Tim started the FL thread with the 1.25B.
I also had very good reason for ignoring it, as I had "just" replaced it (2 yrs ago) and all was good, for a couple of months.

Somehow I forgot my own golden rule of diagnosis:
Anytime a failure occurs in a system that has been previously repaired, verify that repair before moving on.
If I had followed my own rule, I likely would have avoided a lot of grief and aggravation over the past 2 years.

WARNING: The attached pics are not for the squeamish.

Attachment 851Attachment 852Attachment 853

As you can see, one side of the link is pristine, the other, obscene.
When I replaced the link originally, I had packed the holder with dielectric grease (at least now I know what the funky smell has been).
It has obviously been getting hot over a long period of time, once the grease was gone, the case melted and shorted against the body, then the link blew.
The plastic case was actually melted to the hanger.
It turns out that while the connector on the battery side of the harness "looked" fine, it was compromised, either cracked or corroded internally.

A temporary repair has been effected with lots of JB weld, a new link and connectors, mostly to verify no other damage occurred.
I cut back the harness till I found shiny copper.
Fortunately for me, the only casualty during the final failure was all 4 brake light bulbs.

I do have a new holder on order and will replace the harness to the battery at the same time, but at least that can wait until the weather improves.
BB

Wow! Over the years there have been several long threads filled with frustration that thankfully ended with the discovery of a blown (or partially blown) 1.25B fusible link. I probably would have resisted checking that too (considering it had only been 2 years). Perhaps that side had been a bit corroded and didn't make complete contact? Resistance creates heat and heat creates more resistance. The eventual result is complete melt down of the area with the resistance issues. Glad you found it :thmbup:. Tim

About time I updated this thread as I have just found a smoking gun, finally.

Have been in the process of replacing far too much of the left side and had to pull the main harness.
As today is Easter monday and with all the neighbours home, I can't really be panel beating, so into the wiring I went.
The intermittent no start has never really gone away, the fixes have been many but only temporary at best.

Today I cut back the wiring right behind the last repair and it already shows lots of black strands, clearly the issue goes deeper.
I worked back up through the harness, slowly and carefully cutting the coverings off.

Then I found it.
A factory splice on the big wire.
Right beside the splice the little wire's casing is discoloured and noticeably stiffer than the rest of the wire.

To put into perspective where this splice is, its hidden deep in the harness in the section that lies along the frame rail, behind the battery and up into the engine compartment.
I doubt it would be possible to access it without pulling the harness (it goes all the way back to the LR wheelhouse) but for those that have had ongoing issues, it may be worth looking into.

I'll be cutting way back past any visible discolouration and running all new wire and links and crossing my fingers this is the end of it.
BB

By the looks of those connections it could certainly explain a lot. Glad you found it :thmbup:. Hopefully this will be the end of your electrical gremlins. Tim

My AR disposition means that I am never content to just leave things well enough alone. I was looking at the harness today as I was starting to run new wires and realized the wire for the +ve post is only about a foot down the harness and just a wee bit more digging would get me there, then I would know that it was all sound.
I pull out the air tube and a bunch of wires and hoses to gain access to the harness that runs down the frame rail and past the alt. and for the life of me I cannot release it from the frame, finally found yet ANOTHER friggin ground point, and here I thought I had already found them all.
This one hides under the main harness bundle, about in line with the air intake tube, once I found it I was able to extract the bundle enough to strip the tape and holders back to the +ve connection and look what I found on the way there!
Attachment 1555Attachment 1556
In case the pic doesn't do it justice, we are in the main bundle about 6in below the harness T junction (behind the AI tube).
This connection is WAY worse than the last factory splice I found.
So far all I have learned is that I need to go further, this splice hooks into a solid white wire that runs off the passenger side fuse block as well as forward to parts unknown, I can only assume (hope) it heads off to ignition switch land.
Perhaps if I start finding good solid copper wire at some point, I'll be able to convince myself to stop, lord knows this is the last thing I wanted to get into now.
BB

Nice. I just got the engine & transmission back in mine today. The job can be done in a lot less time than it took me, but seemed like everything needed extra care/attention due to age & whatnot. So I spent the entire weekend taking care of all the little stuff. I ended up deleting the rear heater to just so I wouldn't need to waste time replacing all those heater hoses too :yes:.

Whoever it was that said "The road to success is always under construction" must have been talking about 25 year old vehicles :)>:. Tim

Joke's on me.
Being unable to look past even one factory splice, I stopped counting at 20, if I had to guess, I would say I ran into at least double that.
I only found 1 factory splice that didn't show corrosion.
Some of the repairs consisted of replacing 6-8in, the rest though, were significantly more.
Basically everything from the positive side of the battery up to the alternator (incl the pass side fuse block) is new along with the entire starter circuit.
Given what I found, I am actually surprised I wasn't having more problems than I was, will be interesting to see if it makes a difference.
Here's most of what came out.
Attachment 1597

BB

That job just never ends. By the time you get to the last one, the 1st one you did will be corroded :lol:.