My brother in law has asked me to lend him a hand repairing his 97 GTP. I'll admit i'm not a huge GM guy so I was a bit hesitant to agree to dive into a wiring nightmare on a car i'm not all that familiar with, but I am an engineer and I do take pride in solving problems other people give up on! Anyhow here goes:


His engine wiring harness had a severe meltdown where it rounds the top of the radiator, and a few other places.

He unknowingly bought a 98 GTP harness, thinking it was a 97. So The 98 harness is installed. but has some incorrect connectors and extra wires, specifically the C101, C102, C105, and a 20 pin abs connector that don't match up.

At this point he has spent quite a few hours messing with it and asks me to give him a hand.

I've found through alldata that the 97 was a bastard child as far as wiring goes and the pinout to the PCM is entirely different from the 98-04.

So... we got a 98 PCM to replace the 97. Also wired the C101, 102, 105 wires from the car to applicable wires from the 98 harness plugs (but there are about 15 wires too many in the harness!, and a few from that car that don't match anything in the 98 harness!)

The result is the car will start for about 1 second and the ignition then cuts out (dies too fast to be fuel cut, and fuel pump stays running for a few seconds after it dies). Then the car won't start for about 3 min, crank all I want it does nothing, then it will start for 1 second again and die.


Here are my problems i've run into thus far:

The 3 pin connector, which if I remember correctly is c102 (drive side under abs unit area), has from the car side ign+, and +. The corresponding connector in the 98 harness has ign+, and 2 grounds. So only the ign+ is hooked up currently. Do those other wires need to be hooked up somewhere?

Also Should I be using the 97 or 98 fuse box? They seems about identical but I did find in alldata's pinouts that the 97 has about 3 additional spots with ign+ that the 98 does not have. (which I still have not wired in)

I'm stumped, I still have the combination of hooking up those wires I have in question but i'd like to know what is really required for the engine to run, I mean what absolutely needs to be hooked up to the harness from the car and fuse box side of things?

If you got this far, THANKS! I could really use someone who knows the l67 inside out to give me a few pointers on the wiring.


Thanks very much,
Paul