I have my new project in the garage and I am trying to figure out why the battery dies after running the car for ten min.

I will charge the battery and start the car fine but the charge light stays on at idle to about 2200rpm and the gauge also reads low. If I pull the negitive bat terminal while idling it dies but if I pull it above 2K rpm it runs untill the rpms come down and the light comes on.

I am leaning twards a bad alt. but I just don't want to throw parts at it. I also know that it doesn't have underdrive pullys.

any help would be apperciated...thanks

 

Take your altenator off and bring it in to a parts store with a tester. They should be able to tell you whether it's good or bad. And it only costs the gas money to get there.

 

Agreed. Take it off and have it checked.