1991 Chevy Beretta Losing power - Alternator tested/ new ba

DEAFRACER

MEMBER
1991 CHEVROLET BERETTA

Electrical problem
1991 Chevy Beretta 6 cyl Front Wheel Drive Automatic unknow miles

My daughters 1991 Beretta is losing power. She bought the car in February and just recently started having issues. We took the alternator out and went to CarQuest to test it. They said it is fine. Then we replaced the 5 year old battery and it lost power in less time than it took when we recharged the old battery. The only other issue I could assume is a wire ground somewhere that is stealing the power or the alternator is really bad. Is there something else I should be looking for? I am not knowledged in cars but can manage my way around with my Chilton books.

1 Reply

JDL

MECHANIC
16,098 POSTS

Do you have a digital multimeter? Place the leads across the battery posts, everything turned off, the generic spec for a fully charged battery is around 12.6 volts. If the battery is down, take it off and get it charged. Then start the vehicle, take a second reading across battery posts, the second reading should be higher than the first if the charging system is trying to work. The alternator could be fine, could be a faulty wiring circuit.

Another possibility is a battery drain. If the drain is excessive you start by pulling fuses one at a time, when you pull the fuse on the affected circuit, the drain returns to normal. One way to check for drain, take a battery cable loose, use testlite between cable and battery posts, if lite comes on, you have a drain. Check interior lites-- under the hood-- in the trunk. The best time to check for a lite staying on, is in the dark.