[Tiny]

Hi Guys,

Just trying to figure out the wiring on an LS swap that feels like is moving like a sloth.

I have a stand alone harness from a local guy, so there is not much by way of instructions and I myself am not a mechanic.

As such, I have a 74 nova, the ls is a 4.8 from a sierra with the 4l60. I have the motor and the stand alone plugged into the engine. I have used the ls factory cable going to the starter and I am extending the battery cable to fit on the Passenger side (the truck battery was on the driver side).

As for the alternator, I intend to use the truck alternator wire. My question is how to start linking the Nova factory harness to all of this.

Basically, what do I do with the nova factory alternator plug and wires? do I just remove them altogether?

Can I splice the Nova factory cable from the bulkhead to the alternator wire for the truck/motor?

 

[dont]

A stand alone LS engine harness should have connections for all engine functions from the ECU. I’m not sure how the guy built the harness.

 

[Alf]

Tiny, I'd suggest you go to LT1swap.com and read it "cover to cover". That site just about covers everything including how to merge your standalone to the OE chassis harness. You want to have that foundational knowledge.
The guy that reworked your harness should have added a small relay/fuse panel. There is a single small wire (red or pink) coming from that new panel that connects to the wire that used to go to the old + coil wire. That wire is hot on both the "on" and "start" ign sw positions and energizes the PCM.
If the guy correctly reworked the harness he would have left an alternator plug w/ two wires. The output wire goes back to that red box you show in your pictures. I'd use the factory wire (8 ga black), it has a fusible link