E34 525i Touring central locking going ape while driving

[pundit]

I'm having a few electrical gremlins with my 525i Touring.

The central locking will suddenly lock, unlock and then relock again whilst driving.
This happens randomly and without apparent rhyme or reason.

I've read that a possible cause for this can be malfunctioning lock micro-switches.

I will point out that the car comes with an after-market alarm/immobiliser though it has been fitted for several years.

Any suggestions?

[Bruno]

I have never seen that problem while driving. Electrical troubleshooting is a pain. You are probably aware of the rear hatch wires that are always breaking and shorting out.
So could be a problem with the rear hatch wires or the aftermarket alarm that is giving up the ghost. Try disabling the alarm and the lock operation of the alarm.