Central locking, un-commanded spam locks

[lvl100abra]

I'm currently in the process of diagnosing a central locking issue I'm having on my 850 wagon. The central locking system will randomly* lock all the locks.
*The random is not true random, vibration and shaking the car seems to trigger it often, as does the second stage of 2 stage unlock (though neither of these is a guaranteed trigger). This issue started with these events happening very infrequently to once every few minutes even with the car parked and untouched.

So far I have:

• Tried a different central lock relay
• Tried a different alarm relay (swapping between fob and non-fob version)
• Tried unplugging the front door harnesses at the door jam connector
• And unplugging the rear hatch at the connector just before the hinge.

In all cases my phantom lock trigger has remained. I was wondering if anyone else has experienced any similar faults, or any ideas for any other easy diagnosis checks before I resolve to tearing out my interior to search for a shorting wire?

[scot850]

Did you check the tailgate/trunk wiring harness for broken wires?

A bad lock mechanism can cause issues, but normally with just one lock.

Another possibility is the door lock/unlock switch in the center console.

Do you have 2 different working fobs? Try both, but keep the 2nd one well away from the car when testing.

Neil.

[lvl100abra]

After some additional diagnosis, I was noticing that messing with the passenger door harness connector was reliably triggering the locks. I pulled out the door harness and thoroughly inspected it finding nothing wrong. Then I realized the issue could be in the chassis side just past the round connector. I ended up finding a worn though wire rubbing against the knee bolster. I believe this is the root cause of this issue, but I've decided to take this opportunity with the dash out to try and fix an AC leak and some dash rattles so it will take me a bit to get the car all back together to know for sure the issue is gone.