Ok guys im new to all this so hope this is in the right section,
Ive recently purchased a 1995 black m3 which is now my pride and joy,
The only gripe i have is using the central locking via key.
If i put key in drivers door and then the boot and drivers door are only two that open, but if i put key in passenger door then only the boot and passenger door open. so for some reason the passenger and drivers door will not open simultaneously,
Its the same scenario for locking the doors also.
Ive checked fuses etc but im no mechanic so hoping u guys could give me some pointers in where to look to begin to fix this?