Where to put door lock actuator in w126 - PeachParts Mercedes-Benz Forum

81Wagon · #1 10-30-2008, 02:26 PM

I'm installing a keyless entry system in an early w126. It requires an aftermarket actuator be put in the driver's door to lock/unlock the lock.

This shouldn't be difficult. Plenty of people have done this before, including people on this forum. But I've been sitting there staring at the door for over an hour now trying to figure out where to fit this $(*#^ actuator.

Those of you who've done this, where did you put it??

willturnersr · #2 10-30-2008, 05:23 PM

I have an 84 300SD and I installed a vacuum actuator from another car and connected it to the car's vacuum locking system, using the passenger door as a guide. Worked out really well for me.

pawoSD · #3 10-30-2008, 05:25 PM

On the inside of the door right behind the mechanism. It fits....(if its the same kind of actuator I have)....it works amazingly well...I've had it in for nearly 2 years, also, no modifications to the existing system were needed.

81Wagon · #4 10-31-2008, 12:03 AM

Quote:

Originally Posted by willturnersr

I have an 84 300SD and I installed a vacuum actuator from another car and connected it to the car's vacuum locking system, using the passenger door as a guide. Worked out really well for me.

Doesn't this mean you lose the ability to lock all doors by manually locking the driver's lock? (The vacuum pump would only be activated by the keyless entry system, right?)

Quote:

Originally Posted by pawoSD

On the inside of the door right behind the mechanism. It fits....(if its the same kind of actuator I have)....it works amazingly well...I've had it in for nearly 2 years, also, no modifications to the existing system were needed.

I dunno what kind of actuator you had.... Mine are the typical universal type, and I can't for the life of me figure out where I can squeeze it in there. All the space is taken up by the stock "actuator" that sends the lock/unlock signal to the vacuum pump (it isn't really an actuator so why is it so big?? Grrrr).

Here's a picture of my door - the stock gizmo is outlined in green, and the rectangle is a support for the window mechanism that also gets in my way. The actuator is dangling on the right. The inset portions of the door (at the top and just above the green rectangle) get in the way of everything too... Perhaps you can help me pinpoint where I can fit this thing!

pawoSD · #5 10-31-2008, 12:15 AM

Yep, thats the actuator I used as well. Put it on the inside of the door, and it juuuust barely will fit between the switch unit (that you outlined) and the little lifter pin for the lock. You'll be amazed when you see how good the fit is! The bottom of the actuator will literally sit on top of the casing of the existing switch box...I then drilled one small hole (I think.....) and used one existing hole, and screwed it in place. I then devised a way to implement it into the existing locking mechanism. I'd show pics, but I'd have to take my door panel off, and I'm not willing to do that.

Edit: Now that I just realized you have a W123....I am not sure if the doors are the same inside, the W123 door might be smaller and not have enough room....in which case alternate engineering will have to be devised. I've never tried it on a W123.....

81Wagon · #6 10-31-2008, 02:00 AM

Quote:

Originally Posted by pawoSD

Yep, thats the actuator I used as well. Put it on the inside of the door, and it juuuust barely will fit between the switch unit (that you outlined) and the little lifter pin for the lock. You'll be amazed when you see how good the fit is! The bottom of the actuator will literally sit on top of the casing of the existing switch box...

I swear I tried that, and it didn't quite fit. I just checked my other w126 and it seems to have a slightly smaller switch unit, so maybe that'll be enough to make it fit if I swap them out. Thanks.

I have a w123 too but I've already added keyless entry to that one. It actually had plenty of room, through in the end I scrapped the whole vacuum thing and put electric actuators throughout. Now I'm putting keyless entry in my new 300SD (I forgot to update my signature; done now).

pawoSD · #7 10-31-2008, 07:46 AM

Ah ok.....You might have found the issue if the locking switch on the '83's are bigger than on an '82.....I've only installed the system on an '82 so far....my dad has an '83 he might want me to put it on....we'll see how it goes.

I wonder if its possible to get actuators that work at a 90 degree angle from the lock, that would be perfect....

compu_85 · #8 10-31-2008, 01:18 PM

Question: What are you guys using to re-do the vapor barriers?

-Jason

81Wagon · #9 10-31-2008, 01:55 PM

Quote:

Originally Posted by pawoSD

I wonder if its possible to get actuators that work at a 90 degree angle from the lock, that would be perfect....

All it would probably take is to make a little L-shaped (or a bit wider) bracket that could pivot around its center... you could attach a regular actuator to one arm and attach the other to the lock. I considered it for this car but I really didn't want to go to all that effort if I could avoid it

.

Quote:

Originally Posted by compu_85

Question: What are you guys using to re-do the vapor barriers?

I don't bother anymore; So. Cal is a desert anyway. But what I used to do was cut up a garbage bag and glue it on with 3M spray adhesive.

Graplr · #10 10-31-2008, 02:41 PM

I am interested in putting one in my 84SD.

Where did you get your actuator/entry system?

If I'm understand this correctly, the keychain remote signals the aftermarket control box which sends an electric signal to the newly installed door actuator which pops the driver's side door unlocking everything?

Can you take some more pics while you have everything apart?
Thanks!
Ryan

81Wagon · #11 10-31-2008, 03:45 PM

Thanks pawoSD, you set me on the right track with your 90 degree comment... Right after I posted my response to you I remembered where I had seen some of those L-shaped pivots like I'd described: in the locking mechanism in doors of my wagon. So I checked the 300SD and sure enough, it has them too!

I was able to use them to install the actuator at a 90 degree angle! It worked great. Photos forthcoming...

81Wagon · #12 10-31-2008, 04:03 PM

Graplr, you're right on the money... I bought a cheap aftermarket system (Crimestopper CS-865-RKE-II, $30) and a $5 universal actuator off eBay. All you've gotta do is wire up power/ground to a few wires on the aftermarket control box (I put it under the driver's side kick panel - ziptie it to the steering wheel bracket), pull the 2 control wires through to the door (the hardest part of the job) and wire them up to the actuator. It gets a tiny bit more complicated if you want flashing parking lights or a few of the other features, but I'm not going to bother with that.

Here is a photo of the actuator. If you want a photo of the control unit I can take that too, but I don't think seeing it would help you any and it's kind of hard to see where I have it mounted.

Earlier today I pulled the smaller stock lock switch from my 500sel and compared it to the one in the 300SD. It's smaller for sure, but not in any way that would help me squeeze an actuator next to it. One idea I had is that this switch might be able to be replaced completely with a universal 5-wire actuator (basically the same as the 2-wire actuator I was trying to install, with a built-in a 3-wire switch like the stock one in the car). Since I didn't try this, I don't know if the switch in the universal actuator would be compatible with the stock wiring and vacuum pump.

jbaj007 · #13 10-31-2008, 04:04 PM

I've had mine for several years.

I put the actuator near the bottom left corner (~ 2 inches up) as best I remember. Try it with one screw ( I didn't and it looks like I took automatic weapons fire in the door interior sheet metal) and check clearance.

Make sure actuator rod doesn't come up on the existing lock pull rod too high, or the rod at the little allen screw coupler will hang on the interior panel when you replace it and the door will lock but not unlock (BTDT)

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A subscription to this site is WELL worth it just for the pictorial on this EXACT procedure:
http://pindelski.com/Chassis.htm
(no affiliation, just a satisfied user)

sixto · #14 11-01-2008, 12:24 AM

Quote:

Originally Posted by 81Wagon

L-shaped (or a bit wider) bracket that could pivot around its center...

It's called a bell crank. I'm not putting you down. I know what it's called but I wouldn't have thought to make it work the way you did.

Sixto
87 300D

81Wagon · #15 11-01-2008, 12:54 AM

I wouldn't be here if I knew everything! You're much more helpful than my word-of-the-day screensaver - the darn thing just keeps putting up the most obvious, everyday words and I haven't learned anything from it in a month. Now I will have to find some reason to use "bell crank" in everyday conversation or I'll just forget it again

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