Idle problem

1990 BMW 525I

250,000 MILES • 2.5L • 6 CYL • RWD • AUTOMATIC

SAM121212

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Hello,
I noticed when my car is in park position and I turn on the headlights the idle starts to play up and down and when I turn them off it quits. What is the problem here? Thanks

Jun 30, 2017 at 4:34 AM

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Hello,

It sounds like the alternator is getting weak or it has a diode that is leaking. Here is a guide that will help you get the problem fixed.

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Please run this test and get back to us we are interested to see what it is.

Cheers, Ken

Jul 2, 2017 at 7:42 PM