FX4LIFE!

I have a 2011 f150 with a 5.0 that I purchased last May and now has 8600 miles on it.
For about two months now Ive usually just driven the truck about twice a week. since I got my second car going I figured I'll save some gas. So two weeks ago I go to my truck and it's completely dead, couldn't even unlock the doors with the alarm. So I had the truck towed to the dealer where I purchased it, they ran some test and concluded it was a faulty battery. They put a new battery and I drove it home. I drove the truck twice more since that occurred each time putting about 20 miles driving to work and back home. Last time I drove it was this passed Thursday. Sunday morning I go to my truck and its dead again, not completely this time but it wasn't cranking over. I put it in neutral to push it out of my garage, when I finished, then the the battery went completely dead. Once again I towed it to the dealer that same day on Sunday.

Yesterday they ran more test and everything came out fine. They figured it could be something with the alarm draining the battery so I left it overnight so they could have someone come in and check the alarm. Spoke to the service guy today and they found nothing wrong with the alarm. As of now they are clueless and are keeping the truck to try and figure something out.

If anyone knows anything about this or if you've experienced any problems like this I'd appreciate any advice or help. Thanks

BCMIF150

Is the alarm aftermarket? If it is, I would disconnect it and see if it still happens, even if they didn't find anything wrong with it.

If it's not, I don't have any other thoughts.

FX4LIFE!

Alarm was installed by dealer when I bought the truck

PRNDL

There is another person on this forum that has the same exact problem. He generated a thread not to long ago. He found out that his parking lights would mysteriously come on at night a kill his battery. Great job Ford, lets add that to the list of BS problems. Oh yeah, i think his dealer "also ran tests". Found nothing.

PRNDL

Haha, I just found the thread. Look up "park lights stay on and drain battery".

Here is the best part. He had his tires change to a non stock size. His dealer told him that his tires are the wrong size and they confused the computer, so not it kills the battery.

Thanks again Ford.

MKC70

Noticed a draw on my XLT. Found it to be a 220ish ma draw coming from the trailer tow circuit. Pulled the fuse in the passenger kick and it has not come back yet. Talked to a Ford tech I know and he said he has seen it a few times(pulling fuse was his fix as well) while another local dealer said they have not heard of it. Regardless, hope they find the problem for you.

Slowstang

Sounds like a defective SJB smart junction block, this controls most body functions on the vehicle. Without testing I wouldn't know for sure, but I bet that could be your problem.

justinh11

possible bad altanaor

JimFX4

Do you have the Sync system? I read that there was a problem with earlier 2011 F150s where the Sync would stay active after the truck was shut off and would drain the battery. Being that you bought yours last May- that could be the issue. There was a TSB for it and the dealership should be aware. I can't remeber the TSB #.

BCMIF150

That doesn't mean they did it right...