"Simple" LS Wiring Questions

[Texas82GP]

64nailhead,
See the attached picture. The brown wire is the one labeled "IND LIGHT". It's part of the white two terminal plug that plugs into the alternator case. Any idea how/if this should attach to the LS alternator?

Thanks.
John

When you want to tag a member, type the @ symbol before their handle and the forum will notify them, like this 64nailhead

 

[JohnIL]

64nailhead,
See the attached picture. The brown wire is the one labeled "IND LIGHT". It's part of the white two terminal plug that plugs into the alternator case. Any idea how/if this should attach to the LS alternator?

Thanks.
John

64nailhead
See the attached picture. The brown wire is the one labeled "IND LIGHT". It's part of the white two terminal plug that plugs into the alternator case. Any idea how/if this should attach to the LS alternator?

Thanks.
John

 

[64nailhead]

On the B terminal of the 4 wire connector you need one of two things. Either a resistor to a 12 volt source or no resistor and it connected to your idiot light. Either setup acts as an exciter. I've read that you can have both a wire with the resistor and have it hooked up to an idiot charge light.

Do you want the factory charging light indicator in the dash to function? Do you have one?

 

[Zippymac]

This is the best information I have found.
https://lt1swap.com/wiringharness.htm - I made a print out and marked my harness n my 5.3 swap and used a https://www.painlessperformance.com/

The only things left to wire up is Cruise and A/C.

 

[JohnIL]

Thanks again to the geniuses here on the forum, we have the wiring more or less sorted. I thought I would add a follow up message, in case anyone else runs into the same mystery that we did.

The magical keyed 12V pink wire was right was right were Elcam and Texas82GP said it would be. On a gas engine, the pink wire feeds the distributor. On a diesel engine, the pink wire feeds the injector pump. Either way, it is a 10ish gauge wire that supplies 12 volts when the key is on.

The "brake switch" wire was in the main vehicle harness. It is a 14ish gauge green wire and it works exactly the way 81Cutlass explained. With the key on, you will see 12V. When the brake pedal is pressed, the circuit opens.

I don't have a solid answer on the brown alternator indicator wire just yet. I think the LS alternator has everything it needs, but I won't know for certain that its charging until we get a volt meter on it with the engine running.