voltage hand goes down

[little_chevy]

I have a 89 chevy s-10 with a 4.3L engine, when i turn on my lights my voltage hand drops,temp hand goes up,but if you keep the lights of the truck runs fine.Can anybody help me out please

 

[DrMaserati]

Probably need more info than what you have provided. From what you have said it sounds like it doesn't run when you turn the lights on. First make sure the alternator belt is tight. And have the battery checked. It sounds like the battery is either bad, or is not being charged completely.

JP

 

[whitefox]

make sure all the fuses are good.
check the cab/frame ground.
dose the cig lighter work.
my 91 did some thing like what you are trying to say.
the cig lighter was bad/ cab ground so hope this helps.
whitefox