Weird door lock problem

Greetings all,
My 2002 has factory keyless entry as well as a Viper system I had installed many years ago. For the most part it has performed flawlessly, however once in a while after driving and shutting off the ignition I'll go to open door and they are locked. I didn't hit key fob or door lock switch while driving and only seems to happen on longer drives. Any idea on what is happening or do I let the gremlins win.

 

Is it always on the same long drives going the same place or completely random??

Many times I will bump the lock button with my left arm and never take notice till I go to open the Door.

The first thing that comes to mind is interference on the frequency of your system.

#2 wiring getting old and tired dirty just the right bounce or vibration cause the lock circuit to close and lock the doors.

Your Key Fob is in your pocket or another place not able to move?? Not attached to the keys in the ignition ??

Any other odd electrical problems ?

Good luck intermittent electrical problems can be very frustrating .

 

Sitting in truck now and it takes a good push to activate door lock switch. Just bumping it or tapping on it does nothing, so don't think that's the issue.

Yes only notice on longer drives and not to same places. Key fob on key ring so by ignition switch. Could very well be an interference problem as you suggest as there are no other electrical issues.

I can certainly live with it as is if it's just a random frequency issue. I just never thought of that. Thanks for your thoughtful reply.
Cheers

 

My switch on the top of the door moves with very little effort.

A good bump might be enough to move the key fob button.

i had one with so many keys a bump shut off the ignition switch talk about interesting.

Auto trans the owner just never noticed at the restart .

In any case good luck.