Starter wiring for LS

[K5Rob]

Wondering if I can just use existing starter wiring to run my LS or is there a reason it needs to come from the PCM?

This is on my 87 K5 with a TBI 350

 

[Vbb199]

Duplicate

 

[Vbb199]

is there a reason it needs to come from the PCM?

VATS

 

[TotalyHucked]

I used the donor '06 Envoy Denali battery cables/start power wires but for the solenoid/key power wire, I used the original '85 wire. Mine was purple

 

[K5Rob]

Thanks guys. I guess what I was getting at was the 87 bulkhead wiring. I want to use the factory key switch. I believe I can use bulkhead exciter for the starter, hot and crank wires to power PCM… I dont need a start signal to come from the PCM correct??

 

[K5Rob]

VATS

Sorry I should mention I plan on having VATS removed

 

[CalSgt]

Yes… purple wire from bulkhead will trigger the starter solenoid so long as you provide power to the two red wires at the bulkhead.

One of the red wires connects to the positive lug on the starter and the other comes from the… can’t remember, alternator maybe. Both have fusible links, one at the starter and another on the firewall near the brake booster.

You’ll want to retain the brown alternator exciter wire from the bulkhead also

Your PCM probably hooks to its own ECT sensor and you should be able to install a temp sender for your gauge wire (probably green) on the bulkhead.

And a tan wire (probably) for the oil pressure sender. Not sure if the LS PCM’s need an oil pressure sender of their own, if so you’ll need to figure out how to run a secondary sender for your gauge.

If the PCM deals with it’s own coil wiring you can eliminate the pink (probably) wire that powers the ignition coil.

My wire colors are based from my ‘80 but GM is pretty consistent with keeping wire colors the same.