Good morning, I recently bought a 1982 Ford F150 XL 4.9L 300 CID i6 for my daughter and I'm having problems with the battery being drained. I bought a new battery for the truck, installed it and started right up, purrs like a kitten. My problem is the next day I go out to start the truck and the battery is dead. Nothing was left on. So I charged the battery for a bit and the truck started right up. I doesn't die at all while idling. the next day the same thing happens. Rinse and repeat. Can you all tell me what might be the problem. Thanks for all your help and input.

Jason

 

Either there's an electrical draw, or the battery is bad. New parts are not always good parts, so before you replace anything, TEST it. If it passes, the problem is somewhere else. If it fails, test the replacement the same way. If the replacement fails, either you're testing them wrong, or the replacement is bad, too. WHEN you need to replace something, don't buy the cheapest you can find - buy the BEST (which might also be the cheapest, but not usually). I'm VERY picky about batteries & their terminals because virtually EVERYTHING on the vehicle relies on them to work right. I only buy Ford/MotorCraft BXT-65-850 batteries, and I only use solder-on replacement terminals. Click these & read the captions:

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Put all the truck's details into your signature, as this caption explains:

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I had that issue with my 77 F150, and they found the alternator's internal regulator was pulling current and draining it overnight. I am not sure how they tested for that, but it might be worth looking in to.

 

Did you find the problem?

 

1984 F150,12v on 5v reference circuit .... Is PCM dead??