Help! 1984 Ford F250 460 v8, cant figure out why battery drains after a few hours, new alternator...battery holds charge if disconnected....aaaaah im confused!

 

Get a testlight and hook it up like the picture below. If it glows bright, you have a drain. Leave it hooked up, and start pulling fuses till it goes out. When it goes out, that will be the circuit that is pulling the battery down. Remember having the door open with the domelight on will ruin the test, since the domelight will be a drain. If none of the fuses make the light go out, then pull the wiring off the alternator. Sometimes the alt can cause a drain if there is something wrong with it(I know it's new, but don't assume anything).

 

Ok, i did that. All fuses out, still had the light on. SO i disconnected a wire on the alternator and the light went out. It was the wire that WASNT bolted on.....and didnt go to the choke...if that helps at all.

 

Make sure your alternator is wired up like this. I am assuming you have an ammeter gauge in the dash. That is what this wiring diagram is for. The choke is optional.