Tip & How-To about Chevrolet Chevy

Battery drains down on older chevrolet or gmc?

The alternators in these cars and trucks can have a bad diode that still allows them to funtion but drains down your batterery slowly over a few bdays with the key off. replacing the old alternator is the best place to start if your having this problem. then you would have to start troubleshooting the rest of the electrical system if that doesnt fix the problem. that is a much bigger task and often requires special guages, like voltmeters or ampmeters etc. good luck.

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battery drain


bad cell inside battery,so it won;t hold the charge,if battery checked OK,it might be a bad bridge (three diode inside alternator,change AC to DC) in your alternator

Apr 22, 2014 | Chevrolet Avalanche Cars & Trucks

2 Answers

battery slowly drains overnight


could be bad battery,or bad ground.

Jan 24, 2013 | 2004 Chevrolet Avalanche

3 Answers

picture of battery lights up on dash panel, car starts and runs, coolants/fluids are fine


Your alternator is likely bad. Start the car, disconnect the battery, if it stops you need a new one - or head down to the parts store to ask them to test it on the car for you.

Hope this helps.

Feb 18, 2011 | 1997 Ford Escort

1 Answer

Battery light remaining on despite new battery. What could the problem be?


I would have the alternator tested. Usally when the battery light is on, there is problems with the diodes in the alternator. The alternator diodes allows the voltage to go one way, but not the other, when the diodes go bad, power goes the other way, often draining the battery and turning on the battery light.

Mar 15, 2010 | 2000 GMC Jimmy

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