Something is draining my battary
Test the battery itself first , if it passes great, if not replace it. Then do a draw test on the vehicle, disconnect one battery cable, it doesn't make any difference what one you choose, put a test light between the battery post and the cable end, if the light turns on bright you have a draw that can kill a battery overnight, if just a dim glow and I mean dim then you should be good. If you had a bright light the first thing to do is disconnect the alternator electrically, if the lamp goes out or to a dim glow you have discovered your draw inside the alternator. If it is still bright, then you need to remove the fuses one at a time until the lamp goes out, when it does that is the circuit that is causing your problem, find out what systems are on that circuit and remove them one at a time until the lamp goes out then repair or replace. Then put it back together making sure that the light stays out. Sounds complex I know.
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