Don't feel bad about hijacking the thread.. it's old.. (Feb)..
I would pull each fuse one at a time until the .5 drain disappears.. That would pin point the problem area..

 

Sometimes the simple solutions are the easy ones. Now to find a lamp unit that will help indicate the drain and when I pull the correct fuse.

 

Don't mean to state the obvious, but did you remove the hood light when checking for amp draw. .5 is about what that little lamp would draw as well.

 

Good point.. Barry.. Also i would check the glove light.

 

I have already checked to make sure that the hood lamp is not staying on when the hood is closed, and it does shut off. The glove box is a funny one because my brother had problems with his Dodge that included numerous alternators and batteries under warranty until they finally found a broken switch that left the glovebox light on all the time. I guess my initial thought was what sounds to be a common short in a wire from the alternator. I am on my third alternator, although this one bench tested fine, and so did the batteries. Truck runs fine, battery light comes on after sitting over night, but goes out after 5-10 miles on the road. The funny thing is it won't stay on consistently. It will be on solid, then kind of sputter, then go on solid. Don't know if this is because volts are borderline good and it is on the fence for shutting of the dummy light.

I will try the fuse idea today if I get a chance. That would be looking for Amperage draw, right? Do I need to disconnect both batteries for that, or will one still get the results I need? Should disconnect only one terminal and then connect positive DMM lead to positive post and negative DMM lead to negative post and start pulling fuses after I have confirmed the amperage draw is there?

I will also double check the draw that the hood light puts on it and see what it changes to unplugged.

Thanks

 

You have short somewhere in the wiring.

 

How and where did you check and get the .5 amp draw? If you checked it with the hood open, that is why I ask about the hood light. Next question, is there any thing you can do to make the battery light come on, like turn on headlights, blow the horn, slow RPMs, ect.?

 

Are you really "Joe the Plumber"? Nice Avitar.
Got the "approximate" .5 amp draw while checking at the batter posts with one terminal removed. I say .5 amp because the guy that repaired my alternator ran some tests for free and his tester was a simple bulb type tester with two leads. He said that judging by the brightness of the bulb, it was about .5 amps, or comparable to a vehicle radio. It wasn't the hood light because it had shut off before we ran the test.
Nothing I have done seems to aggravate it. I have had the idiot light turn on when my headlights and fog lights are on. Shutting them off doesn't change a thing. I also have high idle on my chip ad if the light is on at normal idle, high idle (1100rpm) does nothing to shut it off. But like I said, it shuts off after 5-10 miles on the road. Going to hopefully remove fuses this weekend and do a current draw test on each one to see if I get anything noticeable. The more I think about it, it has to be a short somewhere. My truck is an '02 that has that "battery saver" feature that shuts off any accessories you leave on after 30 minutes (headlights, glove box, dome light, etc) I've tried it before, and it works. ASSuming that it still works . . . .

Thanks guys.

 

Keep in mind that there is going to be a minimal draw regardless of what you do. That's what keeps the KAM, radio clock, radio preset channels, and anything else that has a memory. That by itself should not pull a good set of batteries down for a very long time.
Check you alt. connections for tightness and make sure you don't have a cracked wire plug.

 

cracked wire plug?

 

I just copied this old thread.. the fellow had a similar battery light problem...

PROLEM SOLVED...Battery light staying on
Ok.after..2- alternators , and many hrs of tinkering, the problem is solved...It was the orange/blue wire in the main harness, broken from rubbing on the drivers valve cover, just as someone suggested early on....spliced a piece of new wire in, sealed it with shrink cover and electrical tape, and bingo..alternator gave out 14.4 volts, and battery light stayed off...whew.. this was a hard one, and hope this info saves someone from the aggravation that I have been through

 

Here is the link for entire thread..
https://www.ford-trucks.com/forums/7...placement.html