I picked up an 88 Gta with a digital dash and 350 tpi engine. The engine harness has been cut up pretty bad on the car. What wiring differences are there between an 88 and 87 harness? I know that the alternator and AC wires are on the opposites sides which I can fix since I did that on my 87 already. Are there any other issues I would run into by swapping the entire engine harness out?

 

Yes,....

There are MANY changes to the F-Body wiring from 87-88. ( Wiper wiring moved to the headlight harness, 87="V" belts but 88=Serpentine, ect.... ) While you can get around many of them by customizing the replacement harness, your best bet is to get a replacement harness from another 88.

 

I got the car home and found out that the computer is also missing from the car along with the TPI engine harness. I am going to proabably try and find a rusted out beyond repair 88 to get the parts from to do it correctly if I try to put it back to "original"...

 

Are the pinouts different for the bulkhead connector as well where the headlight harness and other underhood harness connect to the firewall on the driver side?

 

You're best bet is to get FSM's for both model year cars so you can do comparisons. Don't forget to pick up the electrical diagnosis supplement manuals as well.

 

Not all the wires are different - but some are.

You can use the schematics on my website to figure out what changed from 87 - to - 88.

http://berlinetta.info/C100.htm

http://berlinetta.info/C207.htm

Again; best bet is to use the correct harness. No matter what you "fix" at the C100 connector,.... most of the engine side plugs changed too because 87 was "V-Belt" while 88 was the first year for the Serpentine system.