I have been gradually remaking a 87 GL coupe for the last couple of years. I'm having some electrical probs because I switched it from a fwd auto to a 4wd standard. I have been given a 94 4wd wagon for parts. Any ideas re replacing the 87 wiring harness with the complete 94 wagon harness? Or am I only begging for a world of headaches?

I have been gradually remaking a 87 GL coupe for the last couple of years. I'm having some electrical probs because I switched it from a fwd auto to a 4wd standard. I have been given a 94 4wd wagon for parts. Any ideas re replacing the 87 wiring harness with the complete 94 wagon harness? Or am I only begging for a world of headaches?

 

What kind of problems are you having? I swapped my '87 GL coupe from a FWD 3AT automatic to a RX manual gearbox. Granted, my backup lights don't work and I had to wire up my diff lock to work as well, plus rewire the RX guage cluster to work properly....

I have been gradually remaking a 87 GL coupe for the last couple of years. I'm having some electrical probs because I switched it from a fwd auto to a 4wd standard. I have been given a 94 4wd wagon for parts. Any ideas re replacing the 87 wiring harness with the complete 94 wagon harness? Or am I only begging for a world of headaches?

 

It could be easier.. it is NOT a direct swap AFAIK but it should be largely the same. However, if you are even contemplating it then it suggest a certain degree of ability that would lead me to believe the phrase "world of headaches" MIGHT be a TAD strong.. It is all relative.

 

What kind of problems are you having? Most of the wiring issues from an AT-> manual swap can be coped with fairly easily. The simplest answer might be to find an ECU out of a stick shift vehicle, get the pinouts for each, and snip the plugs for the clutch, neutral sensors etc out of the donor vehicle, and just dovetail the stick shift electrical parts into your AT harness.

 

The ECUs are virtually the same; for all practical purposes I think they ARE the same, 87->94. The "issues" you speak of should be neutral position indicator type codes, right?

 

http://home.comcast.net/~trilinear/EA81_SPFI.html

That is General Disorder's EA82 SPFI onto an EA81 write up. Out of left field, I know, but it tells you how to fool the ECU into thinking things are kosher, and helps illuminate the subject alot.

 

The last thing to say is that the ECU is hard coded to be in a manual or an automatic car. It isnt going to cause problems in and of itself, IF you can fool the auto ECU into seeing the right circumstances at the right times.. and his write up tells you waht those circumstances and times are.

 

Sorry, this post jumped around a bit.. I had to dash to the parts store for some fuel line before they closed in the middle of writing it, AND I am STILL conducting an IM conversation with a good friend who is a thousand miles away... but I hope this helps.

It could be easier.. it is NOT a direct swap AFAIK but it should be largely the same. However, if you are even contemplating it then it suggest a certain degree of ability that would lead me to believe the phrase "world of headaches" MIGHT be a TAD strong.. It is all relative.

 

What kind of problems are you having? Most of the wiring issues from an AT-> manual swap can be coped with fairly easily. The simplest answer might be to find an ECU out of a stick shift vehicle, get the pinouts for each, and snip the plugs for the clutch, neutral sensors etc out of the donor vehicle, and just dovetail the stick shift electrical parts into your AT harness.

 

The ECUs are virtually the same; for all practical purposes I think they ARE the same, 87->94. The "issues" you speak of should be neutral position indicator type codes, right?

 

http://home.comcast.net/~trilinear/EA81_SPFI.html

That is General Disorder's EA82 SPFI onto an EA81 write up. Out of left field, I know, but it tells you how to fool the ECU into thinking things are kosher, and helps illuminate the subject alot.

 

The last thing to say is that the ECU is hard coded to be in a manual or an automatic car. It isnt going to cause problems in and of itself, IF you can fool the auto ECU into seeing the right circumstances at the right times.. and his write up tells you waht those circumstances and times are.

 

Sorry, this post jumped around a bit.. I had to dash to the parts store for some fuel line before they closed in the middle of writing it, AND I am STILL conducting an IM conversation with a good friend who is a thousand miles away... but I hope this helps.

 

 

 

Thanks guys. The problems are that my 4wd electric shift is not working properly, my brake light indicator keeps coming on. I seem to have a short which is killing my battery and WTH, I have to pull the engine because of a weeping head gasket. While it's out anyway... I also have a clean iset of seats and carpet from an 89 turbo wagon that I want to fit into the coupe. Sounds like it's project time.

The problems are that my 4wd electric shift is not working properly, my brake light indicator keeps coming on. I seem to have a short which is killing my battery

 

Yeah, the pushbutton 4wd electricals would be a little trickier (than a D/R, for example), especially installed in an 87 model vehicle. While the S/R is mechanically compatible in an 87, the OEM electricals do not make provisions for a direct swap. You'll probably have to disable/retrofit many of those systems to get rid of those bugs.

You didn't mention if your 87 is carbed or SPFI. If it is carbed, I would consider converting to SPFI. Besides the better intake, your 94 parts car should have the correct ECU and harnesses for the pushbutton 4wd. This may be the best overall solution, since you are upgrading your car, and doing a bunch of disassembly work anyway.

good luck, John