We have a 2007 Ford F150 FX4. A few months ago our battery light came on, followed by our ABS light. Our navigation system went out and the truck made a grinding sound as we were driving. We later determined that this was something to do with the 4x4 system staying disengaged because of the lack of power given out by the battery. (pardon my bad terminology, this is actually my husband's truck, I don't know very much about car mechanics)

Because our battery was dying, we had the battery and alternator replaced b/c we thought this would fix the issue.

Fast forward to now, our battery light is back on and has died a couple of times. There is a draw from the battery but Ford can't diagnose it because the battery light comes on, dies, we jump it, then the problem goes away.

Any ideas where this draw is coming from or why this problem keeps happening?

 

Umm your 4x4 should always be disengaged unless you have it selected to be on. Other than that I can't help you.

 

and its vac op too..

 

+1

 

Remove battery and set on work bench see if it holds a charge. 2007 sounds like a short in the system the hard part is finding it or isolating where it is....

 

Disconnect the ground wire from the battery and charge the battery, disconnect the charger and after 1 hour make sure that the battery reads 12.8 volts.

Now, if you do not have a digital voltmeter that measures DC amps, you will never be able to troubleshoot the problem. Like the video says, $20 at Harbor Freight.

If you have the voltmeter, follow this video. If you show a high amp draw, you have to start pulling fuses out one at a time to isolate the bad circuit, and go from there.

My 5 amp draw killed my battery overnight, ended up being the module that makes the interior lights dim off. But, your problem could be anything.