I'm doing a tpi to carb swap on my iroc. Right now we're trying to pull the whole ecm wire harness (I want to sell the tpi setup complete on ebay). The problem is that the ecm harness and the power wires for the fusebox all go together. What do I have to all wire up to power the fusebox?

 

giving this a bump, i am in the exact same situation.

 

The ECM wiring harness is connected by a harness plug to the interior wiring. It's not hard wired.
For a carb'd car, you only need the wiring from the bulkhead connector.
Also, try using the search.. this is not the first time this question has been asked.

 

I'm in the process of swapping from TPI to Carb myself. After I pulled my engine I sold everything "engine TPI set-up & ecm" . You have 2 choices, either keep the wiring harness so you can modify it for the carb engine & let the new buyer of your TPI set-up find their own or do like I've done & include it with the TPI set-up then buy another harness from someone that's parting out a car. Then modify that harness for your carb swap. I think that it would be extremely tough to try to keep the firewall block & try to split the harness since the tpi system is a wiring nightmare in itself, let aline trying to rob enough to wiring to satisfy the needs for another engine.

Hope this helps,

Bruce