Author Topic: alternator draining battery (Read 3741 times)

dillenger1 · « **on:** January 27, 2009, 03:03:46 pm »

My alternator drains when not running,but it still charges ok.does this happen when the brushes go bad?Will replacing them help?

jtanguay · « **Reply #1 on:** January 27, 2009, 05:10:50 pm »

souds like a diode possibly?

dillenger1 · « **Reply #2 on:** January 27, 2009, 05:36:55 pm »

Now the diode you speak of where is it located?

jtanguay · « **Reply #3 on:** January 27, 2009, 05:40:59 pm »

Quote from: "dillenger1"

Now the diode you speak of where is it located?

no idea. but if it was broken in the 'open' position then it would allow electrons to flow in both directions, draining the battery. it might be in the voltage regulator itself?

when you shut the car off, check the exciter wire for any voltage reading. it shouldn't have any AFAIK.

the caveman · « **Reply #4 on:** January 27, 2009, 09:45:21 pm »

Some bosch alternators have removable brushes and regulator. I don't remember if the diodes are with it,but i don't think so.

Smokey Eddy · « **Reply #5 on:** January 28, 2009, 03:56:21 am »

you 100% sure its the alternator that is draining the batt?