SLK 230 manual use of key won't open doors

[cossiroger]

I have recently acquired my 1998 SLK 230. Central locking works fine using both the remote and the in-car c/l switch but the key will not lock or unlock the doors when used manually. The lock barrel turns freely (and soundlessly) through a quarter turn in either direction but that's about it. I'm worried that should either the battery or a component of the system fail, I'll find myself locked out! Only other possible clues(?): boot locks reliably with key, new MB 74 Ah battery fitted by an independent specialist a couple of weeks ago and the car has a Scorpion alarm, the mysteries of which I have yet to explore. The boot is completely dry. Any ideas would be most welcome.

 

[television]

I would spray some PTFE into the lock through the key hole and see if it will turn ,,do you have a key hole in the passenger door

Welcome to the forum

 

[cossiroger]

Thanks. I've tried WD40 even though the lock barrel turns freely. There is no key hole in the passenger door. Stumped!

 

[television]

Then barrel could be OK

Though the vacuum part is OK it is the switch that is operated by the key, that runs the Pump, but the key also releases the lock catch.

Maybe the mechanism is stuck and the door lining panel will have to be removed to check.

I can give you the details on this

 

[cossiroger]

Thanks again Malcolm. I suspect that it may be the switch; if I listen very carefully when I turn the key, I can hear some mechanical movement within the door but there is certainly no noise form the pump, suggesting that it isn't being triggered. Is it possible to purchase the switch as a discrete unit, separate from the lock itself, or is it an integral part of the lock? Any idea?

Is removing the door panel much of a job?

Regards

Roger

 

[Dec]

I think all Mercedes have a key hole on the passenger door for such an emergency as you describe, it may be hidden under a plastic bung, see pictures in post #7 here… http://forums.mercedesclub.org.uk/showthread.php?p=455630

It would be worth taking the lock barrel part off the door handle to examine it’s condition, also spraying WD40 into the opening that the lock barrel occupied might prove beneficial.

Picture below is of a W202, yours may be similar, the long shaft on the lock fits into the main body of the lock, when the key is turned, the shaft turns with it, moving a switch inside the main body of the lock, which is inside the door. The above is the easiest thing to try first.

Dec

 

[television]

I can let you have the lock removing instructions,,its not too bad a job, so that you can free it up

 

[cossiroger]

Thanks Malcolm and Dec. I have checked the passenger door and there is no cap or provision for a keyhole. The lock arrangement itself is quite different from that shown in your illustration Dec. Basically the handle/lock are inserted through the main door panel and I've established by using a 'dentist's mirror' down the side of the window glass that they are retained internally, so it looks like a door panel job, though I may be wrong! As a temporary measure, I have just rigged up a cable and socked from the battery which can be accessed externally. Just in case of battery failure (light left on etc) so that I can at least charge the battery to actuate the remote locking. Bit chilly working in the garage this morning!

 

[television]

Well I am pleased that you have addressed the problem before it becomes one

 

[cossiroger]

Door lock

An update. My local indie specilist took a look at the lock recently. The manual key operation is strictly mechanical; there is no electonics or vacuum involvement and a plastic component within the driver's door lock had failed. A new lock was ordered and an appointment was made to instal it. In the event, this was problematic; the plastic moulding of the new lock was quite visibly different from that of the old one so that correct alignment was impossible. After a long and valiant struggle on the part of the frustrated technician, a composite of the new locking mechanism and the old plastic casing was installed as a temporary 'get me home' measure. Another lock is now on order. I can't fault the indie for their efforts, but I and they are really disappointed that the new lock casing simply didn't fit. Fingers crossed that the second new lock will be a better fit than the first!

 

[cossiroger]

Final chapter - new lock now fitted and everything appears to be fine. Many thanks to Malcolm and Dec for your offers of help; much appreciated.

Regards,

Roger

 

[newman2000000]

Hi Malcolm,

Following on from my recent post, about replacing the fob housing as it is quite damaged.

I managed to get emergency key out, but it does not unlock the car door or boot. The key turns freely however, so I suspect your lock removal instruction may be of help.

If you have one for, or at least applicable to a CLK W209 then I would appreciate if you would send me this information.

Thanks.

 

[television]

I will have to print this off for you as soon as I can