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General Information => Troubleshooting => Topic started by: dillenger1 on January 27, 2009, 03:03:46 pm

Title: alternator draining battery
Post by: 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?

Title: alternator draining battery
Post by: jtanguay on January 27, 2009, 05:10:50 pm

souds like a diode possibly?

Title: alternator draining battery
Post by: dillenger1 on January 27, 2009, 05:36:55 pm

Now the diode you speak of where is it located?

Title: alternator draining battery
Post by: jtanguay 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.

Title: alternator draining battery
Post by: the caveman 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.

Title: alternator draining battery
Post by: Smokey Eddy on January 28, 2009, 03:56:21 am

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