Painter0711

Hey guys. I have a 1999 trans am. When I start the vehicle I have around 10-11 volts and the car starts and cranks just fine. Pop right off. But the check gauges light comes on and the voltage will stay around the 10 mark for around 10 minutes while driving around and then all of a sudden it?ll jump up to 14-15 volts and stay there while I drive. Alternator starting to go?

sjsingle1

iTrader: (1)

stock alt ? it is weak to begin with

Painter0711

I believe it’s stock alternator. It’s not weak crank. Pops right off. It’s just the voltage reads low

ghardester

Do you have any after-market stuff? Different stereo, dash camera? A stock battery does not deal well with added accesories.

Painter0711

it has just a aftermarket radio and electric exhaust valves. Nothing new has been added electrically. Battery new in February. It just started doing it

sjsingle1

iTrader: (1)

at the MIN.....f bods should have the truck alt

wssix99

iTrader: (5)

It could be a number of things and if its an alternator, the type of alternator doesn't have anything to do with it. A bad alternator is a bad alternator. Obviously, if the car self-corrects the condition, the alternator installed in the car is adequate for the use.

The first thing I would check is the date code on the battery. If the battery is over 5 years, I would change it no matter what. Even if it isn't the problem, the clock is ticking and you are close to midnight... https://www.marshallbatteries.com.au...0August%202016.

You could also have a problem with the exciter wire on the alternator, which is causing the voltage to come up slowly. There could also be loose or corroded cables.

^ I would check all of that and test the battery voltage directly with a voltmeter (when you shut down the car last and then just before you start the car) before yanking the alternator.