Driver's Door / Central Locking System acting neurotically...

[KevLar]

Driver's Door / Central Locking System acting neurotically... SOLVED

Hi gang !

I just replaced the motor in the power lock actuator of my driver's door thanks to a free aftermarket motor from the most generous CandiMan The original problem was that the actuator was not locking the front door, but with the new motor the actuator now seems to work fine based on both a bench test and also running it right off the driver's door harness. The problem is when I use the lock button on the remote key fob, the locking system goes into a lock-unlock-lock-unlock fit that lasts for something like 6 cycles. The second time it happened, the alarm also went off even though I had the door courtesy light button depressed...

I've had the actuator out for almost a year, so I took the precaution of referring to the Rave manual to make sure all the bits went back in the correct place. I never disconnected any of the locking linkages when I removed the actuator, other than the short metal rod that connects the plastic actuator plunger to the rest of the door locking assembly, so I doubt this odd behavior has anything to do with linkages.

There is nothing in the manual that would explain why the central locking system would behave in this strange way, but my intuition tells me that the Central Locking System is detecting that all locks are not being engaged properly, which would imply there's a problem with the driver's door since the other doors have not had any problems.

Any ideas ??

Thanks !

Kev

 

[KevLar]

Spent another couple of hours on this over the weekend without making any progress... It seems as though the actuator works fine when it's only plugged into the door harness, but it goes into a lock/unlock tizzy when it is hooked up to the lock linkage. The odd thing is that when the locking system goes into a frenzy, the driver's door is locking while the other doors are unlocking and vice versa... I've checked the polarity of the new motor as well as continuity of the actuator position micro switch inside the actuator and all seems OK. This leads me to believe that it is not a problem with the actuator, but likely something related to travel and alignment of the actuator shaft.

RAVE talks about reinstalling the actuator so that it is positioned in the middle of the slots and ensuring that "full tolerance on the switching operation is utilised"... I believe I've done that and I tried using the door sill pull and it seems to work fine in conjunction with the actuator, so I am at a loss.

Does anyone have any ideas or experience with this actuator, particularly in terms of adjusting its position ?

Thanks !

Kev

 

[AlaskaRover]

Hey Kev.

Any luck with your lock? I'm having issues with my driver side lock (all my doors lock and unlock with my key fob, but my driver's door is not working). I'm working on a 99 Disco II.

If you have any tips please let me know. Thanks.

John

 

[roving disco2]

Not to hijack the thread... But the same thing happened to my 99 D2 with the drivers door failing to unlock with the fob. Turned out to be a bad door (acuator?), replaced it with a new one and it's been fine ever since.

 

[KevLar]

I just got back inside after spending another 40 minutes working on it, again with no luck. This thing is driving me up the wall ! My story is that the driver's door actuator was not working last summer. I pulled out the actuator and opened it, and the motor seemed to be the culprit. I would still turn, but put out wisps of smoke when powered. I finally got around to getting a replacement aftermarket motor this fall from a generous DWeb member and installed it. Now the actuator works when plugged into the door harness and just hanging there, but the locking system goes into fits when the actuator is actually connected to the locking mechanism...
On its own, the actuator shaft moves OUT as it should when locking, and IN when unlocking, but when bolted to the door and connected to the lock linkage, the actuator is sometimes not moving while the other doors start to lock and unlock repeatedly. It's as if the actuator is skipping or something, but it has plenty of push-pull power to it. Other times the door sill lock pull moves up and down, but opposite from what the other doors are doing. When I hit the disarm/unlock button, everything stops and all doors are unlocked except the driver's door which is locked... Sometimes the alarm is set with the flashing red LED, other times not.
I thought it was a linkage alignment problem, but I'm starting to suspect it has something to do with the little position microswitch inside the actuator. Maybe some epoxy got into there when I put the actuator casing back together, so it looks like I will have to rip the actuator apart again and have a close look inside
Kev

 

[KevLar]

Hey Kev.

Any luck with your lock? I'm having issues with my driver side lock (all my doors lock and unlock with my key fob, but my driver's door is not working). I'm working on a 99 Disco II.

If you have any tips please let me know. Thanks.

John

That was the problem with my truck too at the beginning. All doors would lock using the fob except the driver's door. I only noticed it by chance because the signal lights would flash and I would hear the normal sound of the locks activating, but NOT the driver's door !

First, let me say that I have a '96, so I can't guarantee that my experience applies to the '99. Having said that... Roverjoe made a comment in my original post last year (see link below) saying that a worn nylon bushing at the fulcrum point in the locking linkage MIGHT be responsible for this... In other words, it's possible that your actuator is working fine, but it is just not engaging the lock in the driver's door because of a worn bushing in the locking linkage... What this means is that all the doors are locked except the driver's door, but the alarm is still set, so if you open the driver's door and let the door light switch pop out, the alarm will sound because the locking system does not know that the driver's door is not actually locked... It just knows that the actuator is in the position where the door should be locked.

You should be able to do a quick and painless preliminary diagnosis of the problem by doing the following:

Open the driver's door.
Press and hold the door light switch on the forward pillar to fool the locking system into thinking that the door is closed.
Lock the truck using the fob while listening very carefully for sound by putting your ear on the inner door panel about 6"-8" below where the lock pull is located on the the door sill.
If you hear whirring and clicking sounds coming from there, then your actuator is working and you probably have a linkage problem or worn bushing.
If you don't hear anything, then it's likely there is a problem with the actuator itself, BUT it could also be a problem with the wires in the harness.

Once you have a better idea of the problem, you'll need to pull the inner panel and get to the actuator/lock area. With the door panel removed and vapor barrier pulled aside, look at the behavior of the actuator and lock linkage while locking/unlocking the truck with the fob. Remember to keep the door light switch pressed in !!

If the actuator is moving fully, then suspect a worn part on the lock linkage. On the '96, when the actuator shaft is retracted (pulled IN), the door should be UNLOCKED, and vice versa.

This is the original thread from last year. There is a lot of useful information there, particularly, see posts #26, 32 and 33 on page 2 which relate to the worn bushing and the wiring harness as potential cause.

http://www.discoweb.org/forums/showthread.php?t=53746&highlight=door+lock

Kev

 

[KevLar]

Not to hijack the thread... But the same thing happened to my 99 D2 with the drivers door failing to unlock with the fob. Turned out to be a bad door (actuator?), replaced it with a new one and it's been fine ever since.

Yeah, sometimes it's the actuator, sometimes it's a worn wire in the harness inside the door, and sometimes it's the linkage of the lock mechanism that wears out. Given the cost of the actuator, I would want to make damned sure that it was dead before replacing it, and not something else like wire or worn bushings... I ended up opening my actuator and simply replacing the motor inside with an aftermarket motor. The cost would under $10 as opposed to over $100 for a replacement.
Kev

 

[KevLar]

Dagnabbit ! Well I finally got the problem fixed

The cause was stupidity on my part... Imagine that ! The aftermarket motor I had used to replace the bad motor in the actuator was reverse polarity compared to the original... I never checked before installing it, partly due to stupidity, and also partly because the manufacturer (Mabuchi) was the same for the stock and replacement motors, so I didn't have a good reason to be suspicious. Since I had already sealed the casing after replacing the motor, it was impossible to tell if the motor was spinning the right way, but last night I had had enough, and cracked open the casing once more, and found the polarity problem within seconds.

With the new motor, the locking system now works perfectly So to anyone out there considering repairing a lock actuator with a dead motor, don't let my bad experience hold you back ! It's relatively easy to do and works fine. You'll save yourself a couple of hundreds of dollars compared to replacing a single new actuator !

Kev