Wiring harness question...Please help!

[elantoys]

Okay, so I have this wonderful little 89 Supra that I bought for my son. The problem is, the original engine harness was cut out, yes completely cut from the grey connectors that are still ported to their respective locations. It was running before that happened and had only a few little problems. I thought, no big deal, I'll just find another harness, plug it in and it will be good to go. Wrong. I have been searching diligently for almost a year now for an engine wiring harness for an 89 n/a, auto Supra. No such luck. I only find ones for a 5 spd or a turbo or everything is right except the year. So my question for the mechanically inclined readers is this: Will my Supra accept a harness from a different year car if I change out the ecu to correspond with the swap wiring harness year? And if that is possible, what year should I be looking for and do I have to make changes to the harness at all?

I am not a mechanic by any means, so please simplify my life and point me in the right direction. Thank you!! More importantly, my son thanks you. :biglaugh:

 

[GrimJack]

Yes, if you can get an automatic tranny n/a donor car and pull the ECU and harness, you should be golden.

Alternatively, I think Jay Marks Toyota still can get the complete engine side wiring harness new, give them a call and ask. Might be cheaper than buying an ECU & harness used...

 

[bigaaron]

Alternatively, I think Jay Marks Toyota still can get the complete engine side wiring harness new, give them a call and ask. Might be cheaper than buying an ECU & harness used...

Yeah buy new, even if you find a harness on a car chances are the connectors and wires will be broken in many places. New they are about $400-$500 but they will last another 15-20 years.

 

[whudafux]

I was going to buy a brand new engine harness from Jay Marks. Less headaches. But thats only because I dont like to mess with the electronic part of the car.

 

[Mr.SelfDestruct]

I made the harness for my buddies 20v swap in his ae86 last year.

had to learn japanese wiring diagrams to do it...

but all in all, if you can multi task, harnesses shouldnt give you much of a problem...

 

[Clip]

i think that 86.5-88 use one harness and 89-92 use another. i've read somewhere that 89 was a transitional year, using different connections. correct me if im wrong

 

[bluemax]

My advise is buy a new harness. The connectors do get brittle and break when handled. No matter how careful you are.

The connector on the ECU is different from '89+.
You'll need one for a 86.5-88. You should also remove the ECU and get the part number off of it. You'll probably need it to order the correct harness. I've been told that there are a lot of variations in harnesses.
To remove the ECU, remove the glove box and the plastic cover above the glove box. The ECU is above the glove box, screwed in with a couple of screws.

 

[bigaaron]

i think that 86.5-88 use one harness and 89-92 use another. i've read somewhere that 89 was a transitional year, using different connections. correct me if im wrong

Some early 89 cars had the 87-88 body connectors with the 89-92 ecu. There is also a few different variations on the body connectors depending where your car was meant to be sold. There was a "federal and canada" version and a US version if I remember right, at least that is what I came across in doing 1j swaps. One car had a connector that was different from the others. I would just give the dealer your vin number rather then just the year.