Rear door locks intermittent, why?

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towsey956

towsey956

Well-Known Member
Posts
1,104
Location
Northyorkshire
hi all

98MY d1

My 2 back doors always lock on the remote but then sometimes they don’t unlock, but if I lock and unlock a few times they pop up as normal. I’ve got the door card off and surprise surprise it works fine using a screwdriver to close the lock and hold the light switch in so it doesn’t beep every time I press the button, and everything seems free and moves ok but I’ve oiled it all and put a bit of wd40 in the lock actuator its self but no change, I can’t see any dodgy wiring

And...

The boot door sort of does as it likes, sometimes locks then won’t unlock straight away and sometimes vice versa so won’t lock till I’ve had a few goes, this is a new problem but the 2 back doors have been at it for a while now

Any ideas, does this sound like signs of a common issue

Thanks in advance

Towsey
 
Ah ha

I’m glad you replied, I thinks ive seen you tell someone else the same thing before, are we talking a mm or 2?

With the boot door I put my hand on the handle but I don’t always feel the actuator work with that one

She’s in the naughty corner at the moment but il have a look when I let her out

Cheers

Towsey
 
So i did, for a change i thought i’d use the imperial measurement this time. :)
The adjustment is very fine with moving the actuators mounting plate, so move left or right very slightly then try locking/unlocking with the fob, the 4 screws don’t have to be loose otherwise the plate will flop around and then loose the correct adjustment.

it’s something I learn many years ago with my RR, that ‘know how‘ has been applied to the disco twice, also having to get a seized tailgate actuator motor spinning again which means splitting open the actuator for a look-see inside.
 
Last edited:
So it’s not just a case of moving it up a little bit then to allow for any wear and tear?
The actuator works every time and the complete mechanism seems free but thinking about it sometimes it all sounds a bit steady and the pins almost judder to the top but there seems to be no pattern to this like amount of use/battery charge state/temperature etc. Even when it’s all working what I would call properly at full speed then every now and again it can throw in a misfire

I haven’t looked at the boot door yet but keep the ideas coming ;)

Cheers

Towsey
 
Well its moving it left or right a bit, the holes in the plate are elongated. To much movement and the oppersite will happen ie. back doors now unlocking but not locking, theres no marks to show the exact position... so trial & error.
Dont worry about the pin at the moment, it shouldn't judder, but jump up and drop down as when required.
A quick spray WD or similar GT40 into the door lock at the open door edge as there's always a rear door at least once a year that the pin doesn't pop up straight away, so a part of the lock gets its bit of lub and every thing gets back to normal, the only time those two door are opened is when i'm cleaning the disco and given the open door a quick wipe around. :)
 
Rite I get ya cheers, not looked again yet but il try draw round it’s current position with a marker or sumat. Doors do get a fair bit of use cos of kids going in car and I do the locks aswell as the hinges and check straps etc at least once a year but il have a better go now the door cards off, both rear door outside handles do the creaking groaning noise aswell so il have a look at that, I even bought new springs knowing I was going in there

Cheers

Towsey
 
So why is it, even with the door card off so pin is out aswell and all moving parts feel nice and free, the actuator sometimes moves really slowly? Dodgy wire or actuator? Just been for a play now and for the first few times it either didn't move at all or moved slowly then all of a sudden it works a treat every time. Could it be the 'junction' that lives above the actuator inside the door jamming somehow?

Cheers

Towsey
 
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towsey956 said:
So why is it, even with the door card off so pin is out aswell and all moving parts feel nice and free, the actuator sometimes moves really slowly? Dodgy wire or actuator? Just been for a play now and for the first few times it either didn't move at all or moved slowly then all of a sudden it works a treat every time. Could it be the 'junction' that lives above the actuator inside the door jamming somehow?

Cheers

Towsey
Click to expand...
The actuators a powerful little thing and should ‘bounce’ open and close and move those connecting rods and and lock mechanism without any problem.
So remove the steel rod from the end of the actuator if it’s still sluggish then the actuators motor is iffy and will possibly seize up eventually.
If the motor is now working backwards & forwards correctly with the rod removed then the issue is mechanical and as the rods are usually a loose fit then suspect the lock it’s self, and maybe just requires some lubricating plus a quick splash over the various rod links and up at the rear of the door key lock while your there.
 
So...

Found a spare actuator today so fitted that and checked and oiled the rods and locks etc while the original was off, gets it back together and...still the same!

It’s like the first few times I use it each day it’s not getting enough power or something then all of a sudden it’s fine. Going to try and check power supply with meter and see if it tell me anything.

What controls door lock power and where is is?

Cheers

Towsey
 
Ok a low voltage in the vehicles battery? as a combination of five actuators do take a few amps.
The security ECU sends 12v to the master actuator in the drivers door, then this actuator sends has the 12v to the other four doors via its micro switch.
 
Thanks

Battery not very old and alternator nearly brand new and all ok, and the more I use the locks the better they get not worse if ya get me, if not been used a while they play up for first few times. The only other spare actuator I have is a master so might try swapping that

Will that mess with any coding or is it just swap and try

Can alarm ECU get dry joints like window module?

Cheers

Towsey
 
Nope, the master won’t need any thing other than fitting, and the plate stays in the exact position if you have to remove it to replace the actuator.
Never seen anything mentioned with the security ECU possibly because it doesn’t handle high current loads.
 
Rite cheers

Il fit it if it ever stops raining and hope for the best, if not that then...? The fronts are fine and osr ok most of the time, it might need a second go to unlock every now and again but not too bad and boot lock behaving at the mo, to be honest I’m more interested to find out what it is more than anything I think

Thanks

Towsey
 
OK so...
changed nsr actuator and master in drivers door and checked/lubed all mechanisms still no different. Basically it starts off not working if not been used for a couple of hours and after about 10 lock/unlocks it gets faster and faster till it works fine again

Does anyone know where the junction is that splits the orange and pink wires from the master to the other doors, im wanting to check for dodgy wire etc. The only wiring diagram I have is Haynes

Cheers

Towsey
 
towsey956 said:
Does anyone know of more informative wiring diagrams than Haynes that I can access please

Cheers
Click to expand...
The only additional wire to the controller is one from the security ecu which isn’t show.
 

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Thanks for that

There is also a yellow wire from the drivers door lock barrel micro switch to the master.

So does power go from the control unit to the master then back to the control unit which in turn splits it to all doors or does power go straight from the control unit to the master then to all doors from there and if so where abouts in the car do the wires split from a single orange and pink into 4 of each, I want to isolate individual wires to check or replace them if you get me. I’ve followed the single wires from the drivers door back under the dash then they disappear in amongst all the others under there

I would like to find a plan of where the wires travel within the vehicle if possible, so not just what they go to eventually but the route they take to get there

Cheers

Towsey
 
I don’t think there’s anything to show the route of specific and individual wires within the vehicle... i’ve never see one.
My understanding is the micro switch is there for entering the access code, it also appears that that isn’t shown. :(
Turning the key in the lock each way operates the actuator (to central lock/unlock the remaining four doors) via the connecting rod connected to the lock.

If u have a vehicle for the Japanese market then the central locking is completely different from the UKs so more diagrams in the manual.
 
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