How to Wire Starter in LS Swap???

[PWagon]

Okay, maybe I've been asking the wrong question up till now. So let's try this. How do YOU wire in the starter in an LS swap (into a 86 K5 Blazer)?

A.) Do you use the existing wiring only?

B.) Do you mix both the existing wiring and the PCM to start the engine?

I'd prefer to use the existing wiring, but wouldn't the PCM need to know that it just started the engine before it would make it run?

 

[Larry]

You can do it either way depending what you are doing for an engine harness. You can use the original starter wiring and just changed the end connectors to fit new starter, which is what I did on my 8.1L (same thing I did for the A/C). The other option would be to wire it like the newer GM trucks where the ECM controls the starter relay. The engine ECM is going to know it is running once it sees battery voltage, cam and crank signals. Just tell your tuner/harness builder which way you want to control the starter so they can program accordingly. Hopefully you are using a new harness and not reworking a donor truck harness. I don’t care what anybody says, a reworked harness never works out well for long term reliability.

 

[odin]

.... I don’t care what anybody says, a reworked harness never works out well for long term reliability.

Depends on who re works the harness