2000 Saturn Draining battery

I have a 2000Saturn SL1 and the battery keeps draining… I took the negative cable off and it died. When i got he alternator tested it was fine. While the car is running the alternator will not keep it charged. it just dies again. the lights do not get any brighter when i rev the engine and im not sure if there is a voltage regulator… i havent tested for shorts yet, but i was wondering if anyone could help me.

Well, everything suggests a bad battery. Why haven’t you had the battery tested? If it is more than five years old, skip testing and just replace the battery.

that was my next step. i just didnt wanna spend the money if it wasnt needed… i do have a nice stereo system, so i will try it. THANK YOU!

now that i think about it… wouldnt the alternator keep it running???

Yes, it should. Perhaps there is more here than meets the eye. But you have given us few clues. If there is indeed a problem with the electrical system you must at least start with a sound battery before anyone can diagnose further.

alright…sounds good… i wll reply furher when i get the battery

It sure sounds like a bad alternator to me and is not putting out enough to charge the battery. I believe the regulator is internal to the alternator though. The battery may be shot by now too by being discharged so much. Put a charger on the battery to see if it holds a full charge or not. Personally I don’t trust those guys checking alternators. I’ve had bad ones before that they swore were fine.

If you had the alternator tested on the bench it is still possible the unit isn’t working in the car. Make sure the battery light comes on when you turn the key from the OFF to the ON or RUN position. There may also be a problem with the lead from the alternator to the battery. With a voltmeter reading the voltage at the battery you should see at least 12.7 volts to 14.8 volts while the engine is running around 2,000 RPM.