snakdoc

I have a 2006 F-150 xlt. The battery will drain after a few hours of sitting, I have had the battery and the alt check out both are good> I have also done a amp draw check with a multi meter and my amp draw is only .25ma. when i disconnect the battery over nite it will start the next day with no problem. I also did a light test from the Neg post to the Neg cable and the light goes on, i pulled all fuses and relays one at a time but the light still stayed on. Please help am at a loss as to where to start looking.

Thanks
Bill

Also aftermarket alarm and keyless entry have been disconnected for almost a year

mgbk1200rs

Ground cables, I said this to someone else before, but it is still the right answer, check the cables, most likely your starter motor cables.

blue thunder06

Agreed, and it's not an open circuit. An open circuit will prevent the circuit from working constantly not because of the battery losing charge but because something in the circuit is unplugged that shouldn't be. You have a parasitic drain. When you did the amperage draw test, was the vehicle running? If it was theres your problem, do the test again with it running. You ought to see high amperage. Somewhere around 100-150 amps, also if possible use a vat machine or some other testing equipment other than a multi meter.

Some tests I would do with a DMM

Turn the truck on and measure dc voltage with the DMM leads at positive battery and positive starter, you should be reading low voltage. .5v or less if your getting 11.99v or somewhere slightly below that you have hi resistance, if it says 12v then you have an open in the circuit.

I mentioned a parasitic drain earlier. That's when you have an unwanted amount of current "amps" being drawn from the battery. An example of a controlled parasitic drain would be leaving your dome lights on over night, a door open. Headlights or any other electrical accessory on for too long. Now I can't express this enough but when you do this parasitic drain test leave the truck OFF, if you unhook a battery from a running vehicle it will cause major problems. Unhook the negative cable, put positive lead to negative cable and negative lead to negative post with the meter set to amps. A good general spec for a parasitic drain is 50ma so you shouldn't even see anything with the meter set to amps. so if you get a reading you have a parasitic drain.

If you would like to watch a video on this test here is a guy on YouTube that has a very good reputation for DIY guys like ourselves.

techrep

iTrader: (1)

Agree ^^^

blue thunder06

Did you get the battery issue resolved?

snakdoc

I want to thank every one for their helpful advice. It turned out to be my starter solonoid that was drawing the power from the battery