Questions and Answers

Pontiac Firebird Battery Drain? Q. I just got a 1991 Pontiac Firebird with a 305 in it. I replaced the fan put in a new thermostat and new alternator. The car will crank but when you turn on the lights the battery drains. I took out the battery and put in one from another car I did the same thing but when it was put in the car I took it out of the other car ran just fine no problem at all.

I think the voltage regulator is in the alternator. Can you give me any ideas as to what might be the problem?

Scott

A. You need a simple voltmeter to see if the voltage at battery is over 13 volts when running. If not, the alternator is not charging. Not positive if this is a rebuildable alternator or not. There could also be a problem in the wires to the alternator. If it's not charging I would replace the alternator.