dnchevyman

i have a ls1 put into my sandrail. i have everything working great, except no alt warning light. i already have a volt gauge, but i want a light too. i have the light installed in the dash. can anyone tell me how to hook it up to the alternator so it will light up when i lose voltage??? PLEASE HELP!!!

Rodder

iTrader: (2)

The Fbody 99+ LS1 alternator doesn't have a provision for an idiot light--the PCM controls the alternator. I'm not sure about '98. You can either swap alternators to one that uses an idiot light directly, or get a EE to make you a little circuit to trigger a warning light when the voltage drops below a certain point. I found

Jhankinson

iTrader: (1)

I got mine to work by splicing into the wire that the PCM feeds to the alt. Just as long as you have it going from +12v THROUGH a light then to the alt...it will be ok...as this is how you wire it up to work on carbed and non PCM controlled LS1's. The alt will still ground out at low/high/none voltage situation so the light triggers as usual. Mine has worked great thus far...anyone else chime in on this one.

G-Body

iTrader: (4)

Yep, Jhankinson has it, you will have to connect one side of the light to terminal B on the alt and the other side to a IGN + 12V source.

Jhankinson, I didn`t even think about leaving the computer control hooked up. Did you just "T" into the wire between the PCM and alt? Now that I think about it I don`t see any reason why that would not work, I just never thought about it before.

Rodder, the 98`s do still have an idiot light and their alt is not controlled by the PCM.