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Old 03-15-2010, 11:50 AM
pimpernell pimpernell is offline
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Join Date: May 2007
Posts: 865
Originally Posted by Baer View Post
OK, I'm stumped. The car will not start due to no battery charge.

The alternator tested OK by our mechanic, and the battery has been tested at Sears.

I brought the car to the mechanic and they thought it was the voltage regulator, so it was replaced and appeared to be working.

Tonight my girlfriend took the car to the grocery store and the same thing happened. The car started fine at home, she drove there with lights and defrost on, parked the car and when she came out there was nothing.

Usually I am very capable of sorting out these problems, but I am now stumped. The car jump starts easily, which is why I thought it was the battery. And I am not sure if it is coincidence that it happens to be raining each time this happens.

Any ideas what this may be?

So far things that I have checked are:

Battery (Only 1 year old, and recently checked at Sears)
Negative ground to chassis
Voltage Regulator is new

What else could it be? Relay? Car grounding itself? Bad cable? Ignition? Starter?


If I were you, when your finished with the car for the day, disconnect the battery until the next morning. The next day, reconnect the battery, and try and start the car. If it starts, the battery is holding its charge, if it doesn't, you know the battery is suspect. If the battery passes that test, I would recheck the alternator, by disconnecting all the wires attached to it, including the heavy battery cable, put your multi tester in continuity mode, and place one lead of the tester on the alternator battery connection post, and the other lead to the engine block or any ground point. If you get a continuity reading, it means that one or more of the alternator diodes have failed, and is allowing current to flow from your battery to the engine block. I had that happen to my car, and if the battery were left connected, it would totally discharge in a matter of a few hours with the key in the off position.
96 E300d
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