1975 Chevy Impala battery drain

1975 CHEVROLET IMPALA
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DICKS
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1975 Chevy Impala V8

engine is a chevy small block 400 in a street rod. Everything seemed to work fine for a couple of months, but my last two outings which were about 10 miles oneway and my battery has gone dead and we have had to jump start the car. The battery was checked out to be good and my alternater was said to be okay. Any ideas as to what would drain the battery in such a short time? Could it still be the alternater,starter or battery?
Aug 1, 2009 at 9:42 PM
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MHPAUTOS
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Hi there, check the alternator output at the alternator you want around 13.5 V Min have the battery load tested as it may have a dead cell, and get a current draw test done one the electrical system, if you cant find anyone to do this re post and i will advise on the precess.

mark (mhpautos)
Aug 2, 2009 at 5:39 AM
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URBANMUSHER
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Sometimes it's the little things that we overlook that can be a pain. Check the tension on the alternator belt and look for wear. I had this problem before, alternator was fine, battery was new but driving with the lights on, stereo, heater fan and cooling fan coming on at intervals it was enough to cause the belt to slip to the point of the alternator not charging. After bringing the alternator to a repair shop, the tech bench tested it and found it was okay but the pulley had some blue heat spots on it and there was some fine dust from the belt found on the fins of the alternator. He said that the belt was too loose and the load of all the electrical items drew off so much current that the alternator was actually not turning at one point. A new belt and the right tension solved the problem. He suggested if the belt wears out or the problem persists that maybe the pulleys could need changing. He was cool enough not to charge me for an unecessary rebuild or even his time to bench test it either.
Oct 30, 2009 at 7:20 PM
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