LSx swap electrical questions

[68GMCCustom]

I'm down to the wiring phase on my truck and am not 100% on the starter and alternator connections. What wires from the harness (if any) are you guys using for your starter wires. I have the wh/or/pur and the purple wire (S and R?) ran to it. Of the 3 lugs on the solenoid, one of the 2 large lugs is strapped to the starter, the other is open, plus there is a small lug open.

What are you running to the alternator? My alternator is one of the '08up with the small 2wire connector and the lug on the back...which is for power I thought...so where's a ground, if any? Of the wires ran to it one is 12v from the battery/fuse panel connection.

Its different then what I had and the truck came with... and its been long enough my hard drive just doesn't know where to find the files anymore.

Thanks!

[Clyde65]

on the alternator, the lug is the only thing that goes to the start, the other two are for the PCM to know what is going on and so it can throw a code.

My starter solenoid is hooked up exactly like it was before the swap. If I can get to it, I will shoot a pic of it for you.

[clinebarger]

You only need the purple wire going to the small lug on the starter. You dont need the resister wire any more. The resister wire should be yellow.

The alternator is grounded through the bracket, The lug on the back needs to be hooked to the positive side of the battery.

The voltage regulator is PCM controlled from the factory. But, putting a Resisted ignition voltage (through a light bulb or a resister) to pin 1(lamp terminal) & Straight ignition voltage to pin 2 (Field terminal) should make it charge. (Do not put them on the same curcuit as the ignition box or coils) Heres some connector veiws with pin locations.

[68GMCCustom]

Thanks guys. I pulled my header off for access and started w/purple 12ga wire to the larger lug that was strapped to the started and my wh/or/pu 20ga (now yellow 14ga) going to the small lug, and 12v battery going to the other large lug. I got starter spin but no solenoid action so I reversed the purple and yellow and it worked fine. Does having that yellow wire going to the starter present a possible future problem? Should I just clip it?

I haven't touched the alt. yet but the 2 wires I have going to it (based off of old wiring) are 12v from the battery/fuse panel and a 16ga brown wire that appears to trace back to the gen. light. So I'd be good to go with these 2?

MSD ignition box powers the coil packs and its on my painless circuit boss with the 12v wire being from the existing wiring.

[Pyro]

Originally the yellow wire was used to power the ignition coil while cranking. The purple wire is the one that actually engages the solenoid. You shouldn't need the yellow wire anymore.

[68GMCCustom]

I'll let that wire die then.