1994 Chevy Lumina Low Voltage Reading

KIMBOANN

MEMBER
1994 CHEVROLET LUMINA

Electrical problem
1994 Chevy Lumina Front Wheel Drive Automatic 138000 miles

My Lumina APV engine size 3.8 is running on low voltage. It is running between 10-12 on the voltage reading on the dash. I have replaced the battery and the alternator. Before the alternator, it would run to 0 amps and the battery would die in about 10 min of driving. I have driven the car 3 times since the alternator was replaced--each time for about 10 min, and the voltage is staying right at about 10-12 amps. I know this probably isn't where it needs to be. Any thoughts on what could be causing the problem? Before the alternator was replace, and the volts dropped to 8, the ABS lights would also come on. Need to know what to look into next. Thanks

1 Reply

INTERNETMECHANIC

MECHANIC
700 POSTS

I'd use a digital multimeter, leads touching battery posts, everything turned off. The generic spec for a full charge is 12.6 volts. If the battery is down, take it off and get it charged. Compare the readings across the battery posts, off and engine running. Engine running, the reading should be higher if alternator is working? You can also take a reading at the alternator bat terminal, engine running, just don't get the meter leads or anything caught in belt/s or pulleys. I like to see at least 13 1/2 volts if not more. If the readings are different between alternator bat terminal and battery posts, I believe there is a wiring circuit problem between the alternator and battery.

Engine running, if both readings are the same, low, I'd have to check excite voltage at the alternator, without excite voltage, the alternator may not charge? I need to look at your alternator wiring.