Door locks went bonkers last night...

[hotkarl]

Hey, first post for me...I did a search but couldn't find anything that matched my situation.

97 V6 XLT, loaded.
Been having intermittant problems with the power locks over the last few years, figured it was the actuators on the fritz, and ignored it because even though they were noisy and hung up once in awhile, they would still open and close. Basically it was just the right rear door and rear hatch that had the issues.

Last night I went to unlock the doors with the remote as normal, they opened up fine, but after a few seconds, while I was loading some gear into the back, they locked and all the actuators sounded as if they were engaged and wouldn't shut off, with the remote or manually with the door switches, they just kept screaming, like if you were to hold down the lock/unlock button. Then it stopped and worked fine, figured it was just a weird random thing, so I went back inside for a few minutes to get some more stuff and when I came out again, the doors were locked and the actuators were all going off non-stop again, like if you were pressing and holding down the lock/unlock button.

So now I'm locked out, I try everything, the remotes, the keyless pad,
(I don't have a key for the locks)nothing happens, the doors wouldn't unlock and the actuators just kept going.
After about 3 or 4 minutes I jumped on the running board and rocked the truck back and forth and it stopped. Got in quick, started driving home, and while driving it started again, so I pushed the door button and it still kept going until I actually had to hold down on it while driving.
Got home, popped hood, disconnected battery and haven't touched anything yet today.

So.......Any help would be greatly appreciated, I am a mechanic, but electrical issues are not my strong point, I'm assuming this is a relay/wiring/actuator issue of some sort,
I guess I'm just looking to see if there is short cut to fixing this, also, it's my wife's daily driver.
Even if there is some way of bypassing the power locks/remote system so that she can use the truck until I can figure out what's going on.

Long post, but I'm just trying to give as much info as possible.
Thanks!

 

[MustangP51]

The door key is the same as the ignition key

my guess is a switch is stuck or corroded. Have you ever left the windows down and had it rain?

 

[firepop5]

Probably a relay problem. Could also be a defective switch, but problem occurred after using remote so I would tend toward relays. Three relays in system are located behind trim panel above left rear tire. You can pull 30 amp fuse (#5) from power distribution box under hood till you diagnose problem.

 

[hotkarl]

Thanks for the replies...
I took the door panel off the right rear door because I new that actuator was toast, and it literally fell apart in my hands. It was flopping around inside the door, the factory rivet had let loose and the plastic teeth that go from the pull rod to inside the actuator were nothing more than plastic chips.
Evidently, with this actuator jamming up it must've caused the problem, because once I removed it, the rest of the locks have never worked better.
And like I mentioned, this particular actuator had been on the fritz for a few years now, and I just kept putting off fixing it. Lesson learned.
So thankfully, all I need to do is pick up a new actuator.
It would really have sucked if I had to start tracing wires and checking relays etc...
Anyway, thanks again for the replies.

 

[99eddiebauerv6]

I fixed this on by 99 by removing the fuse. Could only then enter with key. Had to always manually lock/unlock all around. But never had to endure that screeching noise again.