I have done several posts and have about 100 pages printed out, my question is does the original tpi harness have to be cut from the bulkhead connector? I have the engine pulled and all of the wiring laying on the drivers side fender, every thing disconnected excep for the bulk head connector. And there were two big connectors under the dash by the pcm im dont know what they are feeding. Any help would be appreciated.

 

Bulkhead connector does not need to be cut. Last I checked that powered your headlights and wipers.

I had no harness when I did my swap. I endup running like three wires to the C207 connector under the dash and the rest to the bulkhead connector for the guages.

Then for fun, I hooked up the wires for the adl port by running those through an existing hole in the firewall

-jason

 

Your guages, main ignition power(factory distributor), and your start circuit all come off of c100. Most everything else comes off c207.

 

anyone have schematics/diagrams/pinouts of the C207 connector? I haven't seen those anywhere on here.

 

They change from year to year. The 207 connector in the '90 harness from a 90 GTA 350 I have is different than the 207 in my '87 harness from my GTA 350

 

There are some differences in 90 and 91 harnesses. I put a 90 TPI harness in a 91- nothing. I put the correct 91 harness in-started right up. Be careful that you get wiring info for the right years.

 

was the TPI harness cut?? I see no way of removing the original tpi harness with out cuting it from the bulkhead connector, jaysz Ill look again to see if there is a way to remove. Im not going to cut the entire connector, just what is needed to remove the TPI wiring. And then go from there to get the Lt1 wiring done. Im still a little stumped so Im going to istall the engine and everything else and tackle the wiring from there. at least get the back breaking part of it done.

 

The TPI harness unbolts at C100. There is a tiny 1/4 inch bolt in the center. There are two parts to it, one goes to the engine and the other is for the headlights. I would recommend trying to find an engine harness out of a V6 or a TBI car to cut on. TPI harnesses can fetch quite a bit of money if they are uncut. The plugs under the dash are the C207. This powers injectors, speedo, vats, ses light, shift light/TCC.

 

I have seen the 1/4'' bolt and I did not know that the harness would split in half. I have the engine set in there and man its looks really good and sits a lot lower in there. I was trying to save the harness for exact reason of selling it with the complete TPI setup, so thanks for the info.