87 to 89 harness swap

Long story short. I had an engine fire. I am replacing all of the electrical harness'.

I decided to out source this cause it would be a huge time suck. I'm mechanically savvy but short on the familiarity with this project as i would have if i were doing it my self.

I have an 87 4x4, w/ AC, and 4ye motor.

I purchased a complete engine and body harness from an 89 4x4 w/ AC.

My Mechanic tells me the "new" harness is from a 3YE motor. (hmm... 89 3y motor??? seems weird.) The project went fairly smooth. We had to convert come connectors for fuel injectors and sensors but thats easy.

The major snag seems to be that the new harness does not have a place for the ignition amplifyer. He wants a 4Ye harness.

1. Does the 3YE not use an amplifyer?
2. Can the Harness be adapted?
3. Or Do I truely Need to find a 4ye harness?

Was the Seller mistaken on his year? Or did they make a 3ye in 89?

Whats my range of parts matching if I need another harness?

To those who suggest get another van. Thats not what i want to hear. I Considered that; and wighed what it would take to re do the modifications and have chosen this route.

Owning these These vans is about a passion; with all the quirks of keeping them on the Road.

Thanks to all who have contributed to these Forums!

3y engines were used in the 84-85 vans. 86-89 used the 4y. 86-87 harnesses can be interchanged and 88-89 can also be interchanged. I personally wouldn't want to do this swap unless I had the correct 4y harness and wouldn't seriously consider installing a 3y harness (too many potential problems). Another major difference among 4y engine harnesses is automatic transmission -vs- manual transmission. These 2 harnesses are quite different and would create unnecessary problems during a swap. Bottom line, stick with the same year, transmission type, and trim level when swapping such a component. IMO it's worth the wait to find the right part. Can you adapt a harness? Sure, but if your mechanic charges by the hr you'll probably be sorry you didn't wait.

Ignition amplifier??? I think there's a terminology issue here. I'm not sure what component he's talking about. Loosely speaking, an ignition amplifier (not used on the van) is similar in function to an igniter. All Toyota vans 84-89 use igniters so I'm confused on what specific component he's referring to.

I'm not sure about your area but here finding the correct harness would be easy. At any given time there are normally 3 or more vans at our local yards. An engine harness requires a bit of work to remove, so this is something you'd need to get yourself. I hope you get things worked out. Tim

Thanks for the response!
I figured I had some fact checking to do.

It is the igniter thats in question.

The seller confirmed that to the harness is from an 89 4y same options.

I'm not sure why the mechanic thought it was a 3 y.

Ill see if I have wire diagrams for 87 and 88 tonight. What did toyota change?

The chief complaint was that there is no place for the ignitor.

86-87 uses Bosch style injector connectors and 88-89 uses inverted Denso style. 86-87 uses a 1 wire o2 sensor 88-89 uses a 4 wire o2 sensor. Automatic VS manual........there is no overdrive circuit on the manual harness. Manual transmission harnesses have starter relay built into them near the air box (activated by the clutch switch) & automatics are set up with a neutral safety switch circuit (no starter relay). 88-89 California vans had an EGR temperature circuit. These are the only things that immediately come to mind, but there could be other differences. Tim

I finially had time to compare the harness last night.
here's pics:

1 The "new" harness is on the top. The burned up one is on the bottom.
Maybe your better at looking at these laid out, than I am.

https://picasaweb.google.com/lh/phot...eat=directlink



2 just The New harness

​https://picasaweb.google.com/lh/phot...eat=directlink



After going through the harness; it only has 1 of the 2 connectors needed for the igniter.

That new injector harness does not appear to be missing anything. It simply does not have a place for the igniter to plug in.
We would splice it in if we knew where. We already spliced in square connectors for the injectors.
This makes us think it belongs to a 3y. Toyota says 3y's didn't use an igniter. (I think it was integrated into the maf. )

All 3y harnesses used the Bosch style (square) injector connectors. Only the 88-89 used the inverted Denso (oval) connectors. When interchanging a component like this (that's outside of the year range as outlined above) these type of problems are to be expected. I don't know what to tell you other than modify the new harness or get one in the correct year range / with the same options as yours.

It's really not that hard to reverse engineer these things (just time consuming). If the connectors you need aren't burned up then just swap them and the associated wires into your replacement harness. Tim

That's what we can't figure out.

The fuel injector connectors were round. We adapted them to square to fit the 87 injectors.

BUT There is only 1 of 2 connectors present where the Igniter goes.

Also there is a long wire that should go to the distributor on the "89" engine harness. Where as on my old harness (87) that pig tail comes straight off the igniter.

I was able to pull an 87 harness today at P&P.

See link to photo.

https://lh5.googleusercontent.com/-5... Ignighter.jpg

Can anyone identify what wire(s) labeled NCA were they used for.

I have identified the plug that outputs from the igniter to the distributor. It only has 4 wires. The distributor plug has 2 wires. Where does the other 1 go?
At the igniter my NCA wire is White w/ black stripe.

THANKS!

I did a google search and found a similar thread here http://www.automotiveforums.com/t946...n_t_start.html about harness questions. NCA = No Color Available and the OP seemed to think that these wires might be shield wires so no insulation color. I didn't get farther than that but I hope it helps somewhat.

Also the ignition diag from the other forum that has the 87 manual shows two 2 wire connectors going to the distributor. http://toyotavans.org/community/tips...TIONSYSTEM.PDF

Thats good beta. Thanks Old one!

NCA is not a bare wire for me. It is ineed colored. White with Black Stripe. There are other bare wires in the system else ware.

The wire schematic in old one's link gives me hope! I need to look at the harness again to remember all the wire colors.

THANKS EVERYONE!