Can anyone explain this one?
 

87 TDT Ok all of the sudden the door locks activate themselves. If I have the doors unlocked with the key on and then turn off the key the doors will all lock. If I get out of the car and close the door the doors will lock themselves. If I unlock them with the key they will lock themselves again after a few seconds. If the key is in the on position all is well. I am not sure what is causing this, best I can come up with is Gremlins! Anyone got a better idea?

Hmmmm,
1. Christine?
2. The car enjoys your company so much it doesn't want you to leave, trying to lock you in, then becomes insanely jealous/enraged when you do leave and locks you out?
3. What godly figure have you offended lately?
4. Yup, its onnuh them thur gremlin feller's.....

If you have a keyfob, make sure the lock button isnt wedged on with some pocket lint/debris, other than that, I have no clue.

First thing I'd try is unplugging the locks one at a time. Start with whatever one you used last before this happened, if you can remember.

In the doorjamb, pull the large black oval plug out, unplug the connector in the large black oval plug, close the door and try it. Best to do it with the window open, ...

Try each front door, if one of them makes your problem stop, you can leave it unplugged, or pull the lock cylinder:

To pull the lock cylinder, pull out the black plug in the doorjamb in line with the end of the door handle.
Next, remove the allen-head set screw revealed in that hole.
Now the lock portion of the doorhandle will slide rearward toward the doorjamb.
Slide it toward the doorjamb and pull it part-way out until it stops.
Unlock the door, and turn the key approx. 45degrees toward the lock direction while keeping steady light pressure out of the door on the lock and the lock should disengage with the mechanism in the door and pull out.

Being a TD it could also be the hatch lock, since the wires bend each time the hatch is opened and closed. Try first grounding the hatch with an external wire to see if it helps. If it's the lock mechanism in the door, you'll have to pull the doorjamb trim and then the carpeted lower-hatch cover to unplug it.

You can also unplug the pump under the right rear seat to disable the system.

Another thought might be the alarm system under the front passenger floor, you can unplug the alarm system there if it isn't already.

Hopefully someone here will have experience with this problem, and remember the auto-electric motto: It's always the grounds".

Good luck.

I've heard of the central locking pump cam going bad such that the locks cycle continuously or cycle once and stop at locked. Shutting the engine or closing the door shouldn't trigger the cycle, though.

Is the factory security system still functional? If not, disconnect the long box with Becker label under the false firewall in the passenger footwell and see if that stops the gremlin. AFAIK, the security system receives signals from the key switches to the pump. It doesn't relay signals to the pump.

Might there be an aftermarket keyless entry system wired into your car?

Sixto
87 300D

No there is not anything aftermarket in the car as far as security goes. I also believe the factory one is disconnected. This is really strange. The key thing is what is puzzling though.