Tailgate locks randomly

[429CJ-3X2]

I've had my '02 Sport Trac for 4 1/2 years, and every now and then the tailgate randomly locks on its own. More of an aggravation than anything. I usually discover it's locked when the truck is running, or I don't have the key handy. It has the topper/shell on it, so I had a non-chipped key made for the tailgate and keep it in the topper (which I can lock, but rarely do). Now I've bought a bed from another '02 to swap onto my '01, and that tailgate has locked 2 or 3 times on its own just sitting in the yard on some old tires. Fortunately, I also bought the steering column for the wheel, airbag, and clockspring, and have 2 keys for the tailgate. The tailgate on the '01 has never locked on its own in 3 1/2 years. Anyone else have this problem?

 

[koda2000]

That's weird. I've never experienced the tailgate locking by itself on my '01 ST. Knowing how key locks work, I'd guess there's something broken on the lock mechanism that's allowing something to move when it shouldn't. I'd remove the lock from the tailgate and examine it. Maybe compare the misbehaving lock to the one that works correctly in the '01 tailgate you purchased.

I've noticed on my regular 4-door Explorer's that there's a weight associated with the rear window latch. I've never bothered to figure out what it's purpose is, but apparently Ford does some strange things with its locks/latches. I've also examined how the lift-gate/rear window lock works and found it to be a kind of a joke, so who knows what Ford did inside the ST's tailgate.

 

[429CJ-3X2]

Seems weird that both tailgates locking themselves are '02s, and the '01 hasn't done it in 3+ years. Of course, I think my '02 has locked itself only once or twice since I had the key made last year. I could swap locks on the tailgate when I swap the bed (this weekend, I hope), but that won't be a priority. I panicked the first time this new tailgate locked itself because that bed has the factory cover. Then I remembered I had the ignition keys!