Need help finding a Crank/Run Wire for 5.3 swap - 87 Silverado

[Mattchu60]

I'm working on the wiring for my LS swap -wiring is not my strong suit. I have a premade harness which really helps, but I need to find a wire to connect the harness to that works in Run/Start. I tried reading a wiring diagram, but I'm lost.

I'm sure this is pretty straightforward for most - this is a 87 TBI Truck. I still have the original wire harness in place, its just all disconnected on the engine side (since the engine is gone). Is there a wire i can cut and splice into for Run/Start?

[mongocanfly]

i assume your talking about your switch on power...i used the switch on power wire that went to the hei on mine

[Mattchu60]

I believe that is the one - power to the LS wire harness fuse block.

There are a few HEI wires - any idea which one I'm looking to splice into?

[ls1nova71]

The main one is pretty good size, usually tan in color if I remember correctly.

[mongocanfly]

yep..its the biggest wire in that plug...i think tan is correct..but its been awhile since i did mine