Howdy, Working away here and need some help. 70 c10 with a 2002 LS. I have a harness for the ls and a universal American auto wire harness for the rest of there truck. My question relates to the alternator hook up: How do I hook this up? As you can see the LS harness has the plug with the grey wire that runs to the ECU, whereas the American auto wire has the red and brown setup. The American auto wire calls for the alternator wire to go to a plug (4A)that is in the ignition bundle. Not sure if I leave the 4A alone. Will the LS wiring take care of this? Does the ignition switch have to hooked up it? Does the ecu cover this?
Advice and thoughts on this? I might have to call the two companies later, built thought I’d pick some brains here as well.
Thanks all.
1970 Chevrolet C10 Grandpa's -- My first truck -- In progress to shiny Follow the build in the Project Journal 1950 Chevrolet 1-Ton Dually "Ole Red Girl" In the Stovebolt Gallery More pictures here 1951 GMC 9430 1 ton dually--Shiny! | 1972 Chevrolet C20- Rusty- the puzzle box lid for the C10 | 1962 AMC Rambler American- my wife's Parts trucks- 1951 GMC 9300 | 1951-GMC 9430 | 1951- Chevrolet 1300
The LS ECU will manage the alternator for you. You can leave 4A hanging (taped off or de-loomed), then just not worry about the voltage sense wire on the left connector in your picture.
Edit: The LS harness will have ignition switched power. Depending on how it is set up in the painless harness, you might be able to use 4A to feed it.
You will still need the large wire from the alternator to the battery/starter. It is likely that it should be thicker than the AAA harness provides because the LS alternators were higher current than most any of the stock older ones.
Last edited by Fibonachu; 08/19/20244:27 AM. Reason: Add detail
