Anyone Good with Electrical Diagnosis? Doors Unlock, but don't Lock

[Euphanasia]

Brand new here. I'm pretty good with mechanicals, but electrical issues are like Chinese Algebra to me. So here are my symptoms:

With both doors locked, pulling driver's or passenger's inside handle will unlock everything.
With both doors unlocked, pushing the driver's lock button will lock everything. Pushing the passenger's lock button does nothing.

Driver's side key lock locks, but doesn't unlock, and has no effect on the central locking.
Passenger's side key lock unlocks everything centrally, but doesn't lock anything.

I plugged in a keyless entry system, and it will unlock the car, but not lock it.

Any ideas? Sounds like it's somewhere in the "lock" circuit, but I'm not sure where to look. Is there a common fault that I should be looking for, or should I be stripping the doors down to see what's happening inside of the doors?

Thanks

 

[NZ00Z3]

What year and engine is your Z3. It will help in selecting the right wiring diagrams for your car.

Have you tried to lock and unlock the car from the boot/trunk lock? It should lock and unlock all doors along with the boot/trunk.

Many central locking faults stem from a broken wire in the boot/trunk to lid wiring that is clipped to the left side boot/trunk hinge. Do search on the "loom of doom" to see others escapades.

 

[Euphanasia]

It's a '97 1.9. The unlock function works from the trunk as well. It seems isolated to the driver's side switch. I'll pull the door panel and see what's up in there.

 

[mrscalex]

It's a '97 1.9. The unlock function works from the trunk as well. It seems isolated to the driver's side switch. I'll pull the door panel and see what's up in there.

Not the first place to start. You need to start with the boot loom by the boot lid hinge as @Murray Wall has suggested. 9 out of 10 times it's responsible for weirdness like this. The cables fray from rubbing as the lid opens/closes. Sometimes you can see the damage. Sometimes the binding needs stripping back to check.

 

[Euphanasia]

Well I saw this too late, as I had already pulled the door card and removed the latch. Fortunately, it does appear that the central locking solenoid was the issue. The gear mechanism is very sloppy, and the inner switches aren't activating properly. With enough jiggling, I can get the lock mechanism to work.

So, a question--is the lock mechanism in the passenger door the same as the one in the driver's door (albeit reversed)? I ask because I have an extra passenger-side door which may contain the correct part, but I don't want to remove the window track and latch mechanism if the part I need isn't there. The malfunctioning part is 67118353012

 

[Mazza]

From the exploded view,

The part number you mention is No 9

And the parts list calls up 2 off, So I imagine its the same part on both doors.

 

[Geoff Crispin]

Had same sort of problem, bought a second hand one from our member spursfaninacoupe" and all is well but also on my 1.9 it was broken wires in loom of doom. Geoff

 

[Euphanasia]

So...I did need to take the door apart, as there were issues with the connecting rod for the key-lock. However, after quite a bit of poring over wiring diagrams, I sorted it out. Very simple. That tiny switch in the door latch-plate was worn, and so the computer was registering the door as being open. Once I epoxied a bit of ziptie to it, everything worked itself out. Just posting this in case anyone else has the same issue.

 

[NZ00Z3]

Well done, good detective work there.