I purchased 2011 F250 King Ranch Edition about 3 months ago. I'm loving the truck and not had any issues until 3 weeks ago. I locked the truck as usual using the key Fob, and upon returning to the truck, I noticed the doors weren't locked. After some brief trouble shooting, I discovered the the fuse was blown that according to the manual controls just the power door locks. I thought it was strange that a new truck would be popping a fuse so I replaced it...a couple of days later it blew again. This time I was locking the truck with the door key pad. I took it to the dealership and they checked it over and said they replaced the fuse and cycled it numerous times but could not reproduce the problem. The told me that they even put a call in to the Ford engineers and they said check the key pad for water intrusion. The dealership told me they disassembled the key pad and found nothing wrong....lock and unlocked the door some more and the fuse would not blow. I picked the truck up four days ago and the fuse blew again last night. Everything else works...alarm sets and goes off if any of the doors are opened. The only thing that I can find that doesn't work when the fuse is blown is the remote start. Please give me your thoughts on what could be causing the problem.

 

rdenis is the guy who can probably best explain how these systems work. What I learned reading the thread between rdenis and lexus, was that these electronics are complicated and have interdependencies. From an electronics point of view, what I would suspect is the most likely cause is one of the locking motors pulling too much amperage and causing the fuse to blow. An internal problem with one of the control modules is also possible, but I would have thought it would be throwing error codes.

I would hope that water leakage was designed out! But it is possible one of Ford's watertight connectors isn't watertight.

 

My F350 is now blowing the door lock fuse. Mine blows the fuse immediately after I hit the switch. It doesn't work at all. This should make mine easier to diagnose. Calling to make an appointment with the dealer in the morning. I'll let you know what they found.

 

Trying to tie in my toolbox and eventually a tailgate lock I have the new trucks have complicated power door lock systems now a days.

Some of the wiring is stretched a bit too.
Under the drivers door sill there is a bundle that tees off. When I pulled the cover off I found 2 wires that were short enough that they were not in the conduit and were being pinched by the cover. It's all plastic so it won't short, but that is just one small area.

 

I found the same and did like not what I saw. On a further note I hooked up a cap and a tailgate lock to the system, works fine. I hooked them up in drives side door post(wires to rear drivers door) to have room for connections.

 

Where did you find the wires - what colors did you find?

The only thing I have found so far are signal or trigger wires. These only send a signal voltage and are not enough to actuate the locks.

Right now I have a set of 4 relays wired up and ready to install using the trigger signal, but it sure complicates the job.

Did you find the actual solenoid wires?

 

I did not note the colors, my mistake. I had to take the door panel off and take waterproof connector on door post apart. The colors changed from in the door to in the door post. I took connector apart and then traced colors. There were two of the same color in door post, one went to speakers(grd?) and the other was door lock. Wrong one would get you in trouble. I hooked both new locks to this and have had no problems. When I checked the wiring w/volt meter the were not constant, only a pulse, which reversed for open or close. They are enough to work my two locks. Hope this helps.

 

That's it...this is the fatal flaw in the new SD. Let all the Dodge boys and RV.net know they were right all along!

 

Nah - not really, I am done poking and prying without having a wiring diagram or colors available

Guess I'll stick with my 4 relay gig. At least I know it has the power now to run the added locks. My toolbox has 2 solenoids and I'll be adding a 3rd for the tailgate when available.

Doing it the way I did so far at least gets me a 12 gauge wire directly from the battery into the passenger compartment for future stuff.

 

The tailgate lock is avail. Pop N Lock #8255 states Ford F-150 but it works, I have one installed. I had to bend the detent bracket on handle to make it work, minor adjustment.

 

You either have an intermittant short somewhere or a bad BCM.

The door lock relays are actually all solidstate and built into the BCM - they are not serviceable. This one is tough to diagnose, but here is the wiring diagram:



Also, the 12 volt wire that runs to the door lock actuators is located under the door sills - easy to damage the wiring if the sills are pulled and reinstalled incorrectly - I would pull all the sills and take a look at the wiring bundles to see if there is any obvious signs of damage. I had a picture of the actual wire if I can find it I will post it.

 

The Tech at the dealership found a short in a wire in the left rear door, which they fixed.

 

Any chance you could email a higher resolution pic of that diagram?
And if I am reading it correctly, the actuators are powered by a Violet/gray and Gray/ brown wires. Have an idea as to the gauge i would look for?

And if I guess right, they will be in the conduit under the sill, crossing over in the middle "T".

I didn't see any wires that really looked like a heavy enough gauge. Although, maybe the electronics are today where they don't need the gauge capacity of days past.

 

Taken from the work order:

Found chafe at wiring T/O to door flex coupling(Left Rear Door) - Wiring rubbing on
glass run - Repair wiring and add wiring tubing to insulate

The repair took about 1.5 hours. Working well now.

 

I know I don't have an F-150, but I do have a 2008 Ford Ranger and my door lock fuse blew over the weekend. I just got around to getting to AutoZone to purchase 15A and 20A fuses to replace it just incase the 15A blew relatively quickly. Mind you I've already replaced it once a couple months ago because my auto-door locks quit working.

But, I popped in the 15A, tested it it worked! Then I used my remote and nothing. The horn and alarm work just fine. So the 15A blew within a matter of 20seconds. So I thought I'd put a 20A in. It blew as soon as I plugged it in. I'm going to head to the dealer tomorrow since its rush hour and they won't have ample time to do a full diagnostic. So I'll go in tomorrow right after work. Thankfully it's still under warranty. And A BIG Thank you to Swamper for posting your work order information. I'll be surely to print it off and take it with me to speed up the process.