Club 80-90 Forums

I recently had a couple of problems with my Central Locking on my T25 Caravelle 1987. I have fixed the problems and thought it might be useful to share this:

Problems:
a) Central locking opening and closing on its own while driving along! Intermittent but starting happening when driving in heavy rain.
b) Front passenger door lock jamming - very intermittent
c) Front passenger door - when manually locking and unlocking the door lock from inside or using the key the other doors would not lock and unlock automatically although all doors lock/unlock when using the drivers side.

Solution:
From the wiring diagram it is clear the front central locking motors (the black boxes inside the doors which lock and unlock the doors) have a motor to do the moving bit and a switch. The switches connect both front door motors together such that when either one is operated then both motors move. The switch setup is a bit like a two way lighting switch setup in a house where you can turn on or off the light at the top of the stairs from upstairs or downstairs.
Here is what I did:
a) Removed front passenger central locking motor from inside door.
b) Took cover off the motor housing revealing motor/gears and switch and fair amount of water and corroded parts especially the switch. There can be some water inside due to condensation and their is a tiny drain hole at the bottom of the motor housing which allows this water to escape I think. However, I also found that the rubber gater at the top of the motor housing on the outside which seals the top of the motor housing around the arm was perished all the way around. I presume that this is where the large amount of water was getting in when I drove in heavy rain which also makes me think I need to replace the window rubbers.
c) Problem 1 - Copper switch contacts corroded and corrosion bridging between them - clean all this up with fine emery paper and wipe with WD40.
d) Problem 2 - The arm runs along the copper contacts. There is a copper plate in the bottom of the arm which closes the contacts between 2 of the 3 contacts at any one time (one is the Red Feed, two is the Yellow switch wire and three is the white switch wire. The yellow and white wires connect across between the front door motors). The copper plate should be sprung but there are two tiny springs under it which had completely rusted away so the plate was no longer sprung and therefore the plate was not touching the copper contacts properly. Found some new springs (from local shop) - plate now sprung.
e) Problem 3 - Reassembly - Put a tiny amount of silicon sealant around edges of both sides of motor housing before reassembly - I think that the edges were sealed when it was originally assembled. Make sure that drain hole at bottom is clear.
f) Problem 4 - Gater perished - Made my own gater out of a stout plastic bag and cable ties - make sure that arm can move without being hindered once you have put this on.
g) Put the motor back in and voila - it all worked.

Got another problem with boot lid lock intermittently not locking or unlocking properly. Would appreciate anybody's thoughts on that one.

I've been playing around with some Central locking motors too recently (and convienently have a rear C/L door lock on my desk infront of me!). They are actully all the same on all doors but only the cab doors have the red wire fitted to them, makeing them active (ie move them they'll make the others copy), they all actully have the contacts inside them and the spring contact you speek of that breaks - whilst its still there on the rear doors it doen't do anything as they only respond and can be overrided manually which the other locks won't notice.

From looking inside them the cab doors seem to suffer corossion from water but the rear ones seem to have an easyer life so corossion inside them will be less if atall. Still, easy to clean up. I don't think it matters what position you reassemble the wheels inside them but I would put 12v across the white and brown wires before fitting them so they come to rest at the end of a cycle - probubly only a real issue with the active motors.

Rear door, thats an odd one...

[IMG:640:480]http://i40.photobucket.com/albums/e224/ ... 5Small.jpg[/img]
Key in Horisontal position, ie unlocks with C/L - In this case its unlocked as the arm can push the Y shaped thing.

[IMG:640:480]http://i40.photobucket.com/albums/e224/ ... 6Small.jpg[/img]
Key still horisontal, but this time the C/L is locked, so the Y has slid out the way so the arm (with 150 stamped on it) can't push it and open the lock.

[IMG:640:480]http://i40.photobucket.com/albums/e224/ ... 7Small.jpg[/img]
For what its worth, this is the key in the Vertical, always locked, position. Notice that regardless of which end the Y is slid to the arm can't press it.

[IMG:640:480]http://i40.photobucket.com/albums/e224/ ... 8Small.jpg[/img]
Key in forced unlock postion (key not [surposed to be] removable), 45° angle. Regardless of which end the Y is the arm will always open it.

Not towards the top of the picture, near the slider rail theres a white plastic thing - thats where the rod goes that conects to the motor so it can move the Y. Any problems in operation probubly come from here, ie the Y can't slide properly - clean it and regrease, best use graphite lock lube I recon as it remains dry so dirt doesn't stick to it. VW loved to grease the locks but 20 years later they are suffering for it, especally if someone sprayed WD40 in there to "fix it". The C/L motors have a strain releaf system in them so if the lock system jams they won't get damaged or burn out. They may make a loud click noise as this happens though. If you listen to your boot lock you'll be able to tell if the motor has stuck or isn't working.

Another way for a motor to die (cab doors especally) is for the gear wheel spindles to go rusty so noting turns easilly - carefully work the gears off the spindles, sand away rust and regrease so it doen't happen again - they are actully pritty overhaulable as you say. Perfect working C/L isn't too hard to achive.

Cheers Glen
Thanks for the photos and your description.
I came to the same conclusions with regard to how the Y-Shaped thing works. I did this by removing the panel on the inside of the back door and then moving the key and the central locking to different positions and checking what was happening. Of course when I did this, it always functioned correctly! That is until I decided to go and have my tea upon when it did not lock!
I think that my problem is that the Y-Shaped thing is not always travelling to the end. So I will do as you suggested and clean that bar up and see what difference it makes. I think that I will take motor off and clean it up aswell.
I'll let you know how I get on.
Many thanks.

Rear door motor behaving itself (for now). I just cleaned the lock, Y-shaped thing and the bar.
I am trying to source new window scrapers now to stop the water getting in the doors. Looks like I need the one which goes along the bottom (18.95 from JK) and the one which goes up and along the top (34.95 from JK).
The rubber on the existing scrapers has gone hard and started to perish in places and I can see that there is a small gap between them and the glass so they definately need replacing.
I cant believe the price of these things!!
I have sent an email to Wagonbuild and to synchro spares as I have read that they may have some cheaper.
The fix to the central locking did not cost me a bean so I should not complain too much I suppose.

one thing to note when rebuilding the door motors,
when you reasemmble the unit but find it dosent work properly and end up removing / stripping several times to no avail what can happen is that you fit the motor the wrong way!

there is no certain way to fit it , but one way the motor spins backwards!
try refitting the motor the other way.
learn from xperience .

also the small springs for the copper plate you mention, originally i used an old pen spring, but these also tend to rust, so i have recently used the springs from car tyre valves, these seem not to rust! and apart from needing cutting to length work a treat!

Motor: Yeah - Luckily I spotted that the motor had to go round the same way as it came out, that if you turn it over then it looks exactly the same and that it has no markings on it. Thought the O-level physics would come in handy one day.

Spring: I tried pen springs but they were too big. Pens must be bigger round these parts. I used a spring which a kind fella gave me in my local vacuum cleaner repair shop (not many of those about) for free - the motor factors don't seem to sell springs. Even Brighton's famous Nut and Bolt shop did not have any.

Scrapers: Found a supplier who can supply the scraper at the bottom and the other one which goes up and along the top. They are not new but he assures me they are in good nick. For both doors inc PnP it is £60. When I get them I will update.

as another option i have fitted t4 motors to my van , via ebay and a local breaker, one unit was from vw, not cheap but now all functioning, they even fit the side door...the tail gate is different i believe , i left this as all was well..[IMG768]http://i274.photobucket.com/albums/jj26 ... rts001.jpg[/img]