ive got a 1984 ford f150 with an inline six i put a new alternator in it today along with a voltage regulator. the alternator wouldnt charge the battery so put a jumper cable between it and the positive post on the battery and it charges it but if i leave the battery connected over night it kills the battery
any help would be apreciated thnks

 

Welcome to FTE.

Don't hijack other threads, it's considered rude.

 

I ran into the same problem today. What I did today was to try and verify that my wiring was hooked up correctly. So I used this thread for reference. https://www.ford-trucks.com/forums/7...-problems.html. Further into the thread it talks about rewiring the alt and vr to further diagnose the problem. I didnt get that far into it because I skimmed through it ( lack of time) but I did make sure my wiring was hooked up right. It seems the wiring for these trucks is very similar for these years and older. Mine is hooked up exactly how that thread explains. Side note: Dont unhook your battery while your engine is running!!

I would think the reason you battery dies is because it has an electrical drain? There is a way to check for battery drains, i just cant think of it right now.

 

Do the research like John suggested. But it sounds like one of three problems:

1. A bad alternator. Yes, it is very possible to get a bad one from the parts store. A bad diode in it can easily cause a drain when the engine isn't running. However, this doesn't explain having to jump around the solenoid.
2. Incorrect wiring at the solenoid. The wire from the alternator is supposed to stack with the battery cable on the input stud of the solenoid, but if it is on the side with the starter cable the battery won't be charged. But, that doesn't explain the battery going dead over night.
3. Two problems at the same time - incorrect wiring and either a bad alternator or a drain in the truck when the key is off

To test for the drain when the key is off, use a DVM with a 10 amp capability. Pull the positive cable off of the battery and insert the DVM between the battery and the cable - but ONLY with the DVM properly set up in the 10 amp mode. And, make sure the doors are closed and no lights are on.

You should not really be able to measure/see the current on the 10 amp scale if there is nothing draining the battery. If you don't see any, or much, current then you can turn the DVM to progressively lower current scales to see how much drain you have. You'll always have some current draw, but it should be very low, like less than 10 milliamps. BUT, MAKE SURE YOU DON'T OPEN THE DOOR OR TURN SOMETHING ON THAT PULLS CURRENT WHILE YOU HAVE THE METER HOOKED UP! Oh yes, if you have an under-hood light it needs to be disconnected.

If you have much of a draw then you need to figure out what it is. Since we sorta suspect the alternator you could disconnect it. If that isn't it then start pulling fuses until you find one that kills the draw. Again, don't have the meter hooked up when you open the door or the draw of the dome/courtesy lights could blow the fuse in the meter.

 

thnks for the help i will look into it after school school today. i am a mechanics aprentice so i know a little bit about this stuff but i have alot to learn. today i installed 3 speakers behind the seat of the truck i wired them into the original radio and they work pretty good. could that be draining my battery?

 

The speakers can't drain the battery by themselves. They are on the output of the radio and should receive all their current from it. So, unless you are leaving the radio on, the answer is no.

 

today i cleaned out the cab. i found were it is shorting it keeps blowing the fuses as soon as i put them in for the cigarette/horn.

 

While that is A problem, it might not be THE problem that is draining the battery. I say that because if the fuse is blown there shouldn't be any current draw. So, I'd keep looking as there may/probably is another problem.

 

ok i will i got the truck for a hundred bucks off my boss at the shop so im just using it fr the summer as i work on a farm aswell.

 

When you say you installed 3 speakers behind the seat, did you install an amp for them also?