Door lock problem - PeachParts Mercedes-Benz Forum

dresserman · #1 07-27-2004, 06:54 PM

My 1993, 300D front drivers door refuses to lock, with the key or from the inside button. All the other doors lock and unlock with the key, the windows go up and down when required by the key but the door refuses to lock.
What could be the problem?

Thanks

jimmydean · #2 09-16-2004, 06:09 PM

Dresserman:

DId you ever get an answer to this?

Jimmy

dresserman · #3 09-16-2004, 08:51 PM

Not directly. I have been spending much time researching ( door lock ) threads on several sites. What I have not been able to figure out is this. The door lock buttons all go down when you go the drivers or passengers doors and turn the key to the lock position, and all unlock also. BUT, the drivers door will not lock, manually or with the key. IF I'm inside the car and pull the drivers door handle all doors unlock, So, my vacum system must be ok? or can the vacum be bad on just one door? I have yet to find a breakdown on the door lock / handle parts to see what is wrong. Some mechanical part is not doing it's job when asked to..... Just recieved my Model 124 CD's so maybe in the next few days I can figure her out.

Any Ideas?

mpolli · #4 09-17-2004, 12:25 PM

So the button goes up and down fine but the door doesn't actually lock? So it is always unlocked?

dresserman · #5 09-17-2004, 04:34 PM

Mpolli: That is correct, the button will always go up and down when locked or unlocked by eather front door BUT the drivers door is always unlocked.

mpolli · #6 09-17-2004, 05:29 PM

Well, first let me say that I don't have experience with that exact car, however I have worked on several lock/latch mechanisms and they are all quite similar. This is why one Slim Jim will open almost everything. Any way, the short answer is that whatever it is you will have to open up the door. I am guessing you have probably had experience doing this before but if you haven't it usually isn't as bad as you might think as long as you know the "secret recipe" for the particular door trim panel. I am guessing that a linkage has fallen off. There are usually some "bent wire" type linkages which are held on with various clips on the ends. Something could have worn or rusted, or maybe some previous repair was not done correctly. Also could be something broken on the actual latch mechanism from fatigue or maybe a broken spring. Once you have the door open, it should be fairly obvious what the problem is. Worst case you can open up the other side for comparison if you really get stumped. Sounds like a localized mechanical issue at the latch area, not an electrical problem. Hope that helps. Of course I will be interested to hear what the problem actually was.

Mike

psfred · #7 09-17-2004, 09:45 PM

The only way this could happen is if the lock itself has failed or the linkage has fallen off.

You will need to remove the door panel to check, and at least that's fairly easy.

This has been posted before, but I will give you a quick rundown if you need it.

Peter

dresserman · #8 09-18-2004, 12:04 PM

Mike: Thanks, I'll be pulling the door panel off in the next few days. Will post my findings.
Pete: Have a 'cheat' book on the 124 door panel removal. It will be a BIG help.
Thanks.

Snibble · #9 09-18-2004, 12:16 PM

dresserman... if I were to take a guess to what's the problem, it would be that the driver's door vacuum element(thats the black piece that sucks air in and out to lock/unlock the door) is bad. It turns bad when there is a wear in the rubber and its not allowing pressure to build up to do what its supposed to do. I would first make sure that the hoses are fastened securely to the element.. if it is... I would test out the element to confirm.

dresserman · #10 09-20-2004, 09:04 PM

Pulled the drivers door panel and related hardware off today. Took much time to sort out and then remove the latch assembly. Just as I thought, the small lever that actually makes the door lock assembly inside the latch was bent. Not sure what caused this, maybe a few years of frozen locks and much pressure put on the lever, OR, the latch assembly just was in need of a good lube job. The latch assy. was really dirty, much crap came out as I washed the whole thing and let her soak for some time. After bending the lever back and cleaning her she seems to be working properly now.

It is setting in an oil bath untill tomorrow when I will re assemble it into the door for a test run.

My door manual calls for a good lubing with a quality lube like LPS, so this one has never had it as far as I know. Better believe the passengers door assembly will get a good dousing real soon.

IF she still won't work I'll sure let ya all know.

mpolli · #11 09-20-2004, 10:17 PM

Glad to see my psychic powers were working fairly well. Now if they could just tell me how to fix my own car...

haasman · #12 09-21-2004, 02:19 AM

Also while you are "door locking" don't forget to lube the lock tumblers, especially the ignition. This is the beginning of the time of year where moisture and ultimately ice can really screw things up.

If any of them are starting to get a bit "rough" do it now and save major $$$ and time.

Haasman

dresserman · #13 09-21-2004, 01:09 PM

Wonder of wonders, the door is completely re-assembled and everything works SOOOO nice. The hardest part of that re-assembly was that plastic cover that is supposed to be in there, a thieft retardent device, keeps that nasty slim jim away?????
And those holes in the cylinder head. Well there is a splined sleeve that is I think pressed into the head, that's where the splined injector dust shields fit into , it holds them in position and keeps them from turning when you torque the injectors into the head. These holes must just be some type of a casting relief, or used in a machining operation as they don't seem to go anywhere or have a function. UNLESS that's what holds the sleeve in position.

Did give that passengers door lock assy. a good lubing also.
So off to a new repair job.

Thanks for all the info and ideas. I'm sure there will be other bridges to cross, after all it is a Mercedes, right?

420benz · #14 09-21-2004, 09:24 PM

Hay Guys: Hope you can solve my problem.With all doors unlocked with remote,if i push the trunk button to open the trunk,all doors and trunk will lock.If i press the remote again,the trunk will open.

fish4stripers · #15 09-22-2004, 08:38 AM

LPS, great stuff...... Den/ anyone know if you can get it anywhere still?

My lock issue... drivers door lock would not open with key, it would lock vehicle with key so if I locked car I would have to open with trunk or passenger door. When I opened with passenger door, alarm would go off.

Saw on this site, you can swap locks in doors. So I swap passenger lock to drivers door lock and vice versa. Drivers dock lock now opens and locks, but when alarm comes on now.

Anyone got a clue on this one?

Thanks, Jeff