Rear door central locking failure

[fv1620]

I've searched many threads but cannot find my particular problem.

Central locking works fine but now not on the rear door that remains unlocked. As an emergency measure I have disconnected the linkage so that the rear door can only be opened from inside.

Looking at the wiring I can trace two wires that go from this complex of connectors to the latch mechanism.

Blue with White trace & Black with Yellow trace.

I assumed that this would supply some sort of solenoid that is operated by the central locking. With the relevant connectors uncoupled with an ohmmeter I can detect no circuit. On the other connector when flicking the central locking on & off no voltage appears on the corresponding feed wires.

Bit frustrating to find this as on holiday. I can just about operate rear door by pushing on a mole wrench clamped to the linkage arm.

All fuses are intact & the rear window & wiper operate as normal. All the connectors are clean, free of corrosion & I can see no wire breaks or compressions.

I have sprayed WD40 up into where the linkage goes in case some mechanism is not quite going back where it should. Rather mystified as the only eligible source of power to operate a solenoid has nothing & anyway the two leads to this supposed solenoid are open circuit.

Or perhaps I am barking up the wrong tree? Any help gratefully received.

[shokenore]

Curious

My tail gate has never unlocked by the central locking switch.

You do mean the boot door and not the passengers rear doors ?

[fv1620]

Yes sorry by the rear door I mean the very back door, the boot door.

Always used to be part of the central locking as that was the only way it could be locked. Always worked ok but now I find it can't be locked any more

[davejc]

Yes sorry by the rear door I mean the very back door, the boot door.

Always used to be part of the central locking as that was the only way it could be locked. Always worked ok but now I find it can't be locked any more

hi which gen surf do you have?
i have a gen 2 3l and lock works when i start to close rear window and have to open it by hand . if its a gen 3 then yes it should work via central locking .

[fv1620]

It is a KD-KZN185W-GAPXT

I've resorted to operating the boot door by using the key. I have to use it to lower the boot window just an inch to allow the opening lever/handle to engage the cable that releases the locking latch.

Once the boot is open, I use the key to close the boot window & when the boot door is lowered it latches & locks. This is all irrespective of the central locking status.

Another problem has cropped up now I have put everything back together. The boot door always needed a bit of a slam to extinguish the 'open door' warning light on the dash. I now press the micro-switch where the spare wheel holder presses on it & cannot get it to extinguish the warning light.

Is it correct assume that this circuit is normally open & the action of the switch is to close it to operate a relay or is it the other way around?

[surfing*the*waves]

It is a KD-KZN185W-GAPXT

I've resorted to operating the boot door by using the key. I have to use it to lower the boot window just an inch to allow the opening lever/handle to engage the cable that releases the locking latch.

Once the boot is open, I use the key to close the boot window & when the boot door is lowered it latches & locks. This is all irrespective of the central locking status.

Another problem has cropped up now I have put everything back together. The boot door always needed a bit of a slam to extinguish the 'open door' warning light on the dash. I now press the micro-switch where the spare wheel holder presses on it & cannot get it to extinguish the warning light.

Is it correct assume that this circuit is normally open & the action of the switch is to close it to operate a relay or is it the other way around?

Mine is the knz130 but my boot door light is on most of the time & its the latch on the passengers side that seizes open, I did muck about with it for mot last year & got it operating again but didn't last long.....

[fv1620]

Well this has been bugging me for some time. So when it went for its MOT & service I thought I would get the professionals to sort it out. I also asked why the security fob was so unresponsive in getting my 3 clicks to let the ignition to be turned on.

They cleaned the security fob socket but could find no reason why it was difficult to activate. They diagnosed that there was a failure of locking mechanism itself. Several suppliers were tried but to no avail.

So I was rather stuck, one sunny day I had another go myself. Tracing through I could find no voltage got applied to the lock, then I got to the hinge where inevitably the cables in the boot are subject to slight but persistent twisting.

There was the culprit! I should have thought of that first & so should the garage rather than make a duff guess. So much for a professional diagnosis!



So soldered in a new piece of cable & boot locking is back again. The security fob is now responsive, I assume the security control box was lacking the resistance load that was provided by the boot lock mechanism.

[the silver surfer]

Nice follow up mate, I'll be checking the gator on mine too as it's recently failed!!!

[fv1620]

Good luck with it. I wish I had thought of checking it first. At the time I was in a camp site & felt very peeved I was caught without my tools. Even so I could have made a temporary repair. Just glad I didn't get stung for a new lock mechanism.