2001 Mercedes Benz C320 drained battery

2001 MERCEDES BENZ C320
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OLEHUNTERBOY222
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Electrical problem
2001 Mercedes Benz C320 6 cyl Two Wheel Drive Automatic

car always started in warn weather, now that it is cold it is dead after setting all night. battery tested 95% life left at napa alt tested good. was told to place a test light between either battery post and cable. if light is on start pulling fuses. well i pulled fuses in all three fuse locations in the car. also disconnected pwr seat modules. still no luck. need help on diagnosis technique. what i am doing would seem to keep light on anyway. unless the circut is not completed until key on. set DMM to Ma and no draw found. please help
Dec 8, 2008 at 8:12 PM
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MHPAUTOS
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Hi there,

You need to do that test with an Amp meter, and also disconnect the alternator as it may have a faulty diode that ids back feeding , this will not bother the charge rate to any great degree.

Mark (mhpautos)
Dec 8, 2008 at 11:24 PM
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