NL central locking questions

[disco stu]

Hi all. Having an issue where the drivers lock won't drive the other door locks to unlock/lock. Key in the passenger door makes all the locks operate properly, including the drivers lock. Key in the rear tailgate only unlocks the tailgate. Have searched the forum but left with some questions.

My first assumption was that it is inside the door lock actuator. On the 2 pins that are related to lock position on the actuator, they are bridged/connected when the lock is in the unlocked position, and open when it is locked (I think I have this the correct way around, but actuator is out of the car). Is this correct operation?

If that is correct it would then mean the issue is in the wiring or the central locking ECU. Is my understanding correct that the locking ECU is located under the drivers side dash up above the fuse box area?

Is there any other quirks that could be leading to this behaviour? There are some other things not working properly on the interior electrics that I'm yet to chase up, like interior lights, I've read that some weird things are related on the interior

Would appreciate any advice from those who might be able to help

Thanks

Stuart

[stumagoo]

the front doors have 2 mechs to operate the central locking ---- one is the actuator which locks and unlocks the doors the other is a microswitch up on the catch that tells the system if the front door has been locked or unlocked - this is most likely what has failed on your drivers door.

They are not like aftermarket systems where the actuator itself tells the system the door has been locked

[disco stu]

Great, thanks Stu. I looked for a switch on the lock but couldn't see anything so just assumed it was internal to the actuator, mustn't have looked hard enough. Perfect info, thanks. I'll have a better loo once I get home.

Now I'm really glad I went to all the trouble of pulling the sealed unit apart!

[disco stu]

I can't find any wiring at all going to the actual lock still. I've got one unused plug that I can find, link to photo: https://photos.app.goo.gl/td3Um6AeSrVLKvmTA
Its the plug in my hand

Is anyone able to tell me if this is the plug that would normally go to switch on the lock that stumagoo mentioned?

[disco stu]

Can anyone tell me if the passenger door should control all the locks when you unlock that with the key normally? I'm starting to think that someone in the past may have changed the locks and put the wired lock barrel (drivers door) on the passenger side and the unwired on drivers side-ie the wrong way around.

I can't see any wires or even a way to plug into the drivers door lock barrel, but I'm about to rip it out to look at it more closely

[Alex86]

Passenger side does lock/unlock the others when using the key.

[disco stu]

Thanks Alex.

The only thing left that I can think of is that the switch that is supposed to be on the drivers lock cylinder is missing. It does appear that the door trim has never been off in this car though. You can normally tell from the condition of the plastic sheet and glue if it's been off before. Relays are working fine inside the door lock controller, can't really test the rest of the workings though.

I'm not sure what else it could be

[stumagoo]

yep sounds like the barrels have been swapped around some how but I would not have thought the wiring was there for the left door -

[disco stu]

Great-another door trim to remove! Thanks Stu.

Anyone know if you can buy those switches to add to the lock cylinder?

[disco stu]

So, tried bridging the connections in the plug inside the door, that appears to be there to plug into the lock cylinder switch. No reaction, nothing happened at all. I had the old door lock with switch from magna that I wrecked, so wired that in and nothing happened either. It appears that wiring harness is not connected to anything.

I'm also certain that nothing has been changed inside this door since new, given the condition of the plastic sheet etc. The connector was taped in a position where it wouldn't reach the lock cylinder wiring, in a way that no other idiot that worked on this can in the past would have done it. Makes me confident that nothing has been changed inside the door since new.

Surely this car didn't come from the factory with only the passenger side lock controlling all the doors? Can't find any wiring diagram for the door locks, just very basic info in the workshop manual.

Another thing that seems wrong is that there is no method of controlling all the door locks from inside the car. Other cars I own have a lock/unlock switch on the dash. Most/all cars also usually control all the locks from one or more of the other locks/doors. This doesn't happen in this car as it is currently, all doors have to be locked manually once inside. This makes me think that the push button on drivers door should control all the locks, but that part isn't working.

Can anyone tell me if pushing down on the drivers door lock button (the one at the top of the door trim) from the inside causes all the door locks to operate?

[Alex86]

Yep pushing down or pulling up on the drivers lock button that is sticking out the top of the door trim operates all others.

[disco stu]

Thanks Alex.

The signal is getting to the controller from the lock actuator alright, so that indicates that the issue is inside the controller itself it seems. I'll check the relays inside and if its not those then I guess its the IC stuffed meaning replacement of the whole unit

Appreciate all the help so far

[disco stu]

So finally got around to looking further into this before putting the interior parts back on after windscreen install

Turns out it was the clock fuse causing the issues. Replaced that and door locks work from the drivers door. I've also got one interior light now working just not quite sure about the other lights just yet

The clock still isn't working though

[disco stu]

I also suspect that fuse is linked to the radio somehow, and I think I blew the fuse when playing with radio wiring because it was an absolute shambles in there-bare wires sticking out, wires twisted together with electrical tape covering etc. These cars are just bizarre the way seemingly unrelated things are in the same circuit, but the fuse box doesn't mention it

[disco stu]

So this issue has resurfaced in the exact same way, but I have no blown fuses this time. Clock is working, everything else working fine in the interior. Ripped everything apart and tested it all again and the only thing I can come up with is the IC inside the door lock controller. But it wasn't that last time.

I'm tempted just to piggy back the drivers lock control onto the wiring from the passenger door lock switch wiring. I thought the wires from that would join up with the ones from drivers door as they do the exact same job, but they don't appear to. Not sure what else to do