GEN 1 Rear Door Lock Issue

[TomDirt]

There's some helpful f150 youtube videos to show how to replace the actuators but at least 1 where the guy just found a stretched cable causing the right rear door latch to stick.

 

[atdr1]

Check your wiring between the door and the jam. there is a plastic rod inside the loom that will cut into the harness.

 

[rschap1]

I had a broken wire running to mine.
I had Googled it and saw there was a common issue with F-150s.
Real similar to this:

It acted up a little at first.
I thought I could WD-40 the latches.
But a few days later the wire actually broke.
Spliced it back together and been OK since.

 

[BenBB]

I agree, it is either the doorjamb harness or the actuator itself, very common and best to rule out the wiring first. Mine didn't feel like locking all the time and it really pissed me off, as even if you noticed one door didn't lock, you couldn't even force it to lock with the knob. They aren't too expensive to replace last time I looked but if you're patient/industrious/broke you can crack 'em open. They get frickin' nasty:

I did all four a few years ago and no issues since, best I remember there was one or two plastic welds that needed drilling out to separate the halves. And if you go all the way down the rabbit hole on these things there's a thread on some forum that proposes part of the problem is the little electric motor itself, the resistor on the back will prevent the lock from cycling when it overheats. Of course the filth in there doesn't help, and Raptor running makes it moreso (lots of old threads on here as well, early Raptors having issues after a few hard desert/dusty runs). So...I modded the resistors, cleaned them all, packed with white lithium grease, and bagged them in ziplocks...so far so good haha!

 

[TomDirt]

The odd thing (to me) is that the right rear door probably gets the least amount of use. My Right rear is "unlocked" but won't open at all, while the right front just won't unlock using the driver side button or the key fob. But the driver's door has never failed to open using the keyfob or the number buttons. Did Ford use cheaper parts on the doors that get less use?

 

[BenBB]

The odd thing (to me) is that the right rear door probably gets the least amount of use. My Right rear is "unlocked" but won't open at all, while the right front just won't unlock using the driver side button or the key fob. But the driver's door has never failed to open using the keyfob or the number buttons. Did Ford use cheaper parts on the doors that get less use?

I doubt they've carried engineered obsolescence quite that far, they all looked the same internally to me. But on mine one press of the fob unlocks the driver door, a second press unlocks the other three, and lock makes them all lock at once. So really the driver's door should wear out first and may be a little beefier since it's the only one with a rod for the key cylinder. But my theory is the rears just ingest more dust...

 

[1BAD454SSv2]

My Drivers front door lock S H ! T the bed last week , at the car wash cannot open door from outside handle. Ended up opening from inside handle crawling through passenger side . Took apart figured rod fell off or something , nope broke internal to mechanism . Bought new one have yet to install plus new moisture barrier it was all cracked and fell apert. 12 years sitting in arizona heat i guess.