GM TBI conversion on a 304 CJ-7

**dave w** · 03-07-2016

Yes.

The computer will supply the "Ground" to the check engine light when there is an error. The other wire of the light is connected to the ignition switch ("On").

dave w

**Texasdave** · 03-22-2016

Working on the wiring harness and and I am unsure of which wires I need and which I don't. I have two multi-port plugs in the wiring bundle that connects to the wiring bundle inside the vehicle (1990 Chevy Pick up donor vehicle). DO I cut these out? I think I should but I'm unsure what they connected to inside the cab. I feel like a bomb tech do I cut the pink wire or do I cut the green/black wire. Only good thing, at least I won't blow myself up.

**dave w** · 03-22-2016

Figure out the ECM wiring first, here is a link to the 1227747 wiring schematics: http://www.gearhead-efi.com/Fuel-Inj...Information-42

dave w

**Texasdave** · 03-31-2016

When I removed the wiring harness it had a bulkhead connector, or at least I thought it was. In reality the wires go straight through and are covered by this plastic goop. I heated the goop and it melted allowing me to separate the wires. This makes it easier to work with them. BTW I was careful not to get it so hot that it melted the wire coating.

**fastacton** · 04-01-2016

Originally Posted by Texasdave

When I removed the wiring harness it had a bulkhead connector, or at least I thought it was. In reality the wires go straight through and are covered by this plastic goop. I heated the goop and it melted allowing me to separate the wires. This makes it easier to work with them. BTW I was careful not to get it so hot that it melted the wire coating.

Yep, that's the fun part!

**Texasdave** · 04-21-2016

Because I cut the wires short to the ALDL I am going to have to add some wire to be able to mount it. What is the preferred method? Soldering and shrink wrap or unpinning from connector and crimping new wire?

**lakedrifter** · 04-21-2016

hey your in my neck of the woods:)

I'm not at expert at ECMs and programming, but I have worked in wiring a couple years now. When these guys mention re-pinning you usually see it when upgrading to a new style of ECM. They are basically moving the wires around to the corresponding pins for that ECM. Some may re-pin for looks. Some may simply wack and soldier the wires where they need to be. The only time I can see actually having to "re-pin" is if you may some how degrade the quality of the circuit. I know that some wire pairs are twisted and some wires have to be shielded. I'm not sure how I would handle those if I came across one that I needed to cut.

In my case, I'm doing a direct swap. I cut my entire wiring harness from the doner and all my wires are soldiered and shrink wrapped for the ECM.

Heath