Ok, I'm finally starting the wiring on my LT1 swap. I pulled out my thirdgen ECM, but there is still a set of wires (see #1) attached to the bundle of wires that comes in behind the fenders. What does it go to? If I'm supposed to do most of the harness wiring from the C100 bulkhead connecter, what am I supposed to do with this connector? Also, what is this other shiny box for(see #2? Do I keep it?

 

Pic

 

Circled item #1 is connector C207...learn to love it, that and C100 on the firewall driver side are your new best friends!

 

#2 is the air bag control module. don't touch it. if you don't already know, the black box beside it is the VATS module.


Also, just curious, why did you pull the entire dash?

 

What is the C207 connector used for, I'm not using any of the wires at all out of it. I have all of my stuff going through the C100 connector.

 

Suspicions confirmed. I was pretty sure it was the airbag module. So many yellow covered wires going to it.

Along with replacing the engine, I stripped my interior for a complete overhaul as well. New seats, carpet, vinyl covered center console... I didn't pull the interior just because I'm doing the swap, but it's making it pretty easy to get to all of the wires I need though.

How would I have gotten to the thirdgen ECM if I hadn't pulled the dash though?

 

simply unbolted it

I know when I pulled mine out I just removed the 2 or 3 small sheet metal screws holding it to the dash supports under the passenger side of the dash. The only time I completely loosened the entire dash was to get to the VATS module.

 

I'm pretty sure I won't be taking the dash off again any time soon. Not a fun task.

 

So, what do I need to do with the C207 connector? I never saw it come up in any of the wiring diagrams, maybe I missed it. Can someone point me in the right direction?

 

I traced mine out and think that the pink/black wires are the injector and ignition wires. I didn't use them since I got the underhood fuseblock from a car.

 

So if I have the fuseblock, I can just disconnect the C207 and my car will still be happy?

 

So far it seems to be working fine, I have power to my injectors and coil...just can't figure out why my fuel pump relay will not engage.

 

Astoria18,
I dug up this link on the Instrument Panel connector and some pinout info. It may not match entirly but gives info on what some of the signals are in that connector.
From there you can figure out if you need to keep them or tie into them for anything. Most of the branching links still work from that thread. There were two discussions about them.
My site still has my conversion diagrams too as well as the 90' schematics.
Like i said, It doesn't match exactly but may help narrow your search.
Jp

https://www.thirdgen.org/techbb2/sho...%2FP+connector

 

The circuit contents of C207 vary from year to year. Oil pressure gauge circuit, fuel pump relay output to pump, etc. tend to migrate back and forth between C207 and C100 each year...darn crafty GM engineers.

 

I can't be for certain what year harness I have, I only know it's from a 90-92 Trans Am and my oil pressure, temp, tach come through the C100 connector on that harness. I finally got mine to fire last night with nothing plugged into the C207 connector except for a couple of power lines that I used to power the underhood fuseblock.