shane254

can you alternator drain your battery when not running if it still charges when it is running

vikgerasim

What do you mean?
Can the alternator drain your battery when the car is not running? No.
Can the battery drain if your alternator is broken? Yes and it will.

bgriffey

The answer is yes... an alternator is a three phase device and one phase can be defective while the other two continue to operate. The diodes that make up the rectifier section are normally to blame for the failure. There are six diodes and if one fails, you can get partial charging and battery drain problems like you are experiencing...

87_300zxT

I think this is what is wrong with my car, my batt will not charge but the car will run off the alternator, but not well