Hey guys.

I'm trying to finish up an engine swap (2.8- 5L) and have got everything mechanical squared away. Everything from the driver side connector is hooked back up, and the engine runs (roughly still, but i credit that to not having checked vaccum lines or timing).

I took a second harness which runs to the ecm out the passenger kick pannel, from the donor car. From this second harness:

One connector runs to a little module I took from the other car (connector is iether blue or green, 3 circles OOO).

Theres a heavier red wire with a pin connector (I'm thinking this runs to battery where there is a cut wire on the positive lead.) there are a whole bunch of cut wires, another 3 circle connector farther down, and a few squre-like connectors that i can't place from the harness.

Everything came from a 84' Z28. The engine isn't the original 5.0 H.0 (the previous owner swapped in a 350, then put back another 305 later) And I don't believe the distributor, or carbourator are computer controlled (esp when comparing to the carb and dist i pulled from another car that had the HO, and that have places to plug a few more of the wires into) Also the Z28 had AC and cruise, the recieving car has niether.

So, Where do the rest of the wires go? What do you guys think, should i axe the second harness, or change to the carb and dist from the HO and try and plug more stuff in.

Also, if anyone has a wiring diagram of the second harness, i would appreciate a link or attachment. I couldn't find it on the 85' wiring diagram page

 

The harness on the right is the ECM wiring. It goes to the sensors and driven devices that the ECM uses to control the engine. It has nothing to do with cruise, alternator, gauges, A/C, accessories, or any other feature of the car; it is for all practical purposes a part of the engine. In fact, if you had gone to one of the assembly plants where they were putting these cars together, and looked at the engines on the shelf, you would see the harness already attached from the engine plant; then when they put the engine into the car a sit roleld down the line, they unroll it, run it into the pass cabin, and plug it into the ECM.

If you don't run the ECM, you don't need it. Carefully unplug it from everything, peel it back, unplug it from the ECM, remove the clip that holds it to the cowl bulkhead, and store it in a box or sell it to somebody that needs one. If you do decide to run the ECM, you'll need to repair whatever has been hacked off of it. It's all or nothing: if you use the ECM and the computerized carb & dist, almost every bit of it is essential; and if you don't, you don't need it at all.