more questions re my '85 300sd (w/ photos)

[its_snowing]

sorry for posting again, but i'm new to this - new to the point where its tough for me to search through old posts and find pertinent information by myself, as im not familiar enough with the car to decide what problems are similar enough to mine to be helpful. i build banjos, not cars... it will take a bit for me to catch on.

in any event, i have a few problems im trying to tackle on my car (1985 300sd, 306,000 miles). the first, as i have already posted, is regarding the locks.

problem 1) the drivers side lock will not lock when the door is open, nor will the key unlock the door. the only way to lock or unlock it is from the inside. however, i discovered that my vacuum system seems to work, as locking all the passenger doors also automatically locks the trunk. does anyone have any ideas as to what i might check on next?

problem 2) what the heck is this? i was searching for the rear fuse box in my trunk, and found this set of wires, two of which are cut, that dont seem to lead to anything. i also notice this bracket, which is mounted to the back of the trunk, seems to be empty... any ideas?



problem 3) my trunk is getting moisture in it. i couldnt help but notice that the area under the rear windshield looks like something raised from the titanic. is there some way i can cover this up effectively enough to stop water from coming in?



thats it for now. the car runs fine (converted to wvo), though i fear that, had i known better, i probably wouldnt have bought the car. i also need to have the shocks replaced, and the rear windshield is suffering from the dreaded delamination. which brings to mind... anyone know a good mercedes shop in the boston area? im not ready to tackle the suspension myself.

thanks!

[pawoSD]

"Problem 1" This is not a problem, this is a feature, this prevents you from locking your keys in the car by making sure you lock the car with your key from the outside, with the door closed. The drivers lock is the switch for the vac system that opens/closes all other locks, including fuel door and trunk. Later models the trunk lock also activated the system.

"Problem 2" Looks like some wires from an old alarm or audio device that was mounted there, or perhaps a car-phone system at one point.

Problem 3, this one is an actual problem...your lower deck under the rear window up inside there is likely almost rusted out. We had this happen on our car too, its common once the rear window seal starts leaking as it ages. We did a huge re-construction on ours...and managed to save it. The issue you see there from in the trunk is only the begining of what is going on up in there. Search for rear window rust threads and they will show you everything.

Here is my thread dealing with this problem, so far it has held up perfectly!

W126 The HORRORS - Rear window RUST!! Help!

Good Luck!

[its_snowing]

oh man, looks like i will have to deal with a moist trunk. however... will i even be able to install a new windshield and ignore the rust, or will i likely have to deal with structural problems that will make it impossible for the glass to fit in properly?

as to the lock... i think its mechanical, as i cant even open the car with the key through that side. i'll have to take it apart and have a look.

[Hatterasguy]

Problem 3 is the only one you have to worry about. The wires look aftermarket, trace them and cut them out if they no longer do anything.

I have a post from two years ago when I yanked the rear window in the SDL to fix this. Mine was rusted that bad, yours is probably pretty bad. But you won't know until you get the rear window out. Mine is starting to bubble again even though the car on gets wet once in awhile back there. I am beginning to think the only way to fix it is to cut the old metal out and have new metal welded in, followed by a body shop spraying some good paint on it. At least thats how I'm going to do it on the second try.

[its_snowing]

yeah, i can turn the key, and it feels the same as it does on the passenger side, which works. i can hear a little clicking, and can feel something happening inside the door. but the lock doesnt budge one bit. additionally, i cant even press or raise the lock button with the door open. it is completely frozen. but again, once i close the door, i can lock it by hand, from the inside.

[Hatterasguy]

With the door closed can you lock it from the outside with the key?

[its_snowing]

nope. with the door closed i can neither lock it with the key, nor unlock it with the key. in short: the key turns in the drivers side door, and it feels like tis catching, but nothing happens. it seems like there is something wrong with the locking mechanism.

[Jeremy5848]

The key in the driver's door moves a vacuum valve which locks or unlocks all four doors, the trunk, and the fuel flap. If you can turn the key in the lock cylinder but nothing happens in response then something has broken or become disconnected. You will have to remove the door panel and get at the vacuum valve. There are instructions on this forum on how to remove the door panel without breaking anything (use the search function).

[Hatterasguy]

Ok then something is broke. The door handle comes out as one unit, once you get it on a bench you may be able to figure out what is wrong and fix it.

A new one runs about $350, and the tumblers are cut to your cars vin so you don't have to use two keys.

[cdplayer]

Originally Posted by its_snowing

nope. with the door closed i can neither lock it with the key, nor unlock it with the key. in short: the key turns in the drivers side door, and it feels like tis catching, but nothing happens. it seems like there is something wrong with the locking mechanism.

This may not be the case, but I have a 1984 500 SEC. I too cannot lock or unlock the drivers door with the key. A previous owner had an after market keyless entry system installed. In doing so the factory alarm was deactivated and the key mechanism of the drivers door affected by the keyless actuator.:fork_off:

[pjc]

Shocks are the easiest part of the suspension to replace, so don't fear them. You can do it with basic tools, without removing the springs, and without the need for realignment when you're done. The question you need to ask yourself, though, is: Are you sure it's (just) the shocks, and not something else, like ball joints?

pjc

[JimmyL]

Originally Posted by cdplayer

This may not be the case,

Your signature is out of control............

[pawoSD]

Originally Posted by Jeremy5848

The key in the driver's door moves a vacuum valve which locks or unlocks all four doors, the trunk, and the fuel flap. If you can turn the key in the lock cylinder but nothing happens in response then something has broken or become disconnected. You will have to remove the door panel and get at the vacuum valve. There are instructions on this forum on how to remove the door panel without breaking anything (use the search function).

The W126 does not have engine-vac locks, the drivers door lock controls an electrical switch that runs an electric vacuum pump in the trunk, which operates all the locks. It sounds like the key mechanism is broken and does not catch when he turns the door tumbler....disassembly and potential replacement will probably be needed.

[its_snowing]

i suppose that one thing im wondering, with respect to the rust, is whether or not i can simply put a new windshield over it and seal it up, and whether that new seal will prevent more water from getting in.

[TheDon]

spray some white lithium grease in the key hole for your lock, who knows when the last it was greased...