rob_fed

Per my previous post I requested the wiring diagram for the w204 door looks.

https://mbworld.org/forums/c-class-w...ml#post6650958

Basically, the w204 doors consist of the cosmetic interior door panel which holds all of the electrical switches, radio speaker and the interior door lever. The basic design has been used for years in MBZ cars.

Once the interior door panel is removed, you will find another aluminum door panel cover. This both a cover and a structural and the vapor barrier between the cosmetic interior panel and the actual door frame. It should be noted that the aluminum cover is riveted to the door frame and the power window tracks and motor are mounted to the aluminum cover via rivets and screws. When I put it back together, I was able to use bolts and nuts for the window track mounts.

To access my broken door lock actuator, you must remove the aluminum cover and exterior door handle to get the latch removed from the door.

The driver's side door lock actuator takes the most beating for two reasons, frequency of use and an obscure design with the door lock control module that allows the motor to still be pulsed while the door is open, even though the door lock is mechanically stopped so you don't lock your keys in the car.

I had everything apart with door lock actuator/latch assembly out of the car in the hopes of trying to replace the tiny electric motor and/or other mechanical parts. But I found the assembly had a lot of plastic catches and was afraid that if taken apart, I could not even use the broken unit manually.

These are typical actuator motors inside the door latch:


Well, since I had everything apart, I decided to try to use a universal actuator, the type commonly used by alarm installers. To piggy back on to the existing door lock push rod.




This is what I had, this is a 5 wire unit and you only need to use a 2 wire unit.

After much to do with voltage testing and other wiring investigation, you only need to use two wires that go to the original door latch motor. The colors are grey/black and grey/blue the second color is the line stripe color.

When it is all said and done, these two wires provided the 2-3 second pulse to the original actuator motor. I disconnected the original motor as it was not doing anything due to it's failure. I connected the universal actuator wires blue to the grey/black and the green to the grey/blue. This same pulse makes the new actuator go up/down to unlock/lock.





What I am not showing is the actuator mounted behind the aluminum panel. And the parallel push rod I bent to connect to the factory push rod.

But now that I know, I feel that I could of did all of this on the outside of the aluminum cover inside the cosmetic door panel.





I would have to cut away some of the strengthening ribs, but there seems that there would be enough room. This would make this fix very easy.

Aftermarket door lock actuators last almost forever providing they are installed properly without binding.

ghlkal

Thanks for taking the time to post this.

Lots of good information

Moto-P

Did just as described but on the outside of the aluminum panel, and worked like a charm, with a lot more power in the motor than any of the stock units!

There was a pocket of space just under the door striker area in the interior panel where the aftermarket actuator could reside, so it went right on top of the aluminum panel there for a straight shot at the vertical rod just under the door locking pin.

Caution, the motor connected, the two gray wires do pulse with the load resistance of the original motor, so it is best to just kill the old motor, and use the said leads only into the aftermarket motor. I originally tried to parallel wire it with original motor wired in as well, but it wouldn't work. Cut the original motor wires, and problem solved.

$10.00 to fix a $400 dealer install replacement. Not bad!

THANKS FOR POSTING!

danfranjr

Hi Guys,

Appreciate if got any picture to show the installation of universal actuator without dismantling the aluminium panel.

I am wondering how do i hooked the actuator with the door lock.

Thank you.

rob_fed

Typically, the actuator comes with some hardware not shown. There is a push rod and small screw clamp connector. You must bend the the push rod and connect it to factory push rod connecting to the locking post at the top of the door panel. From memory, you can create a nice bend and clamp the rod behind the rubber bellows grommet.

Josh.A.Hussey

Im guessing you no longer need the wiring diagram?

danfranjr

Hi All,

Thank you for the prompt reply. I shall get my guy to assist me on this. Hopefully it works as currently i am having issues with both front and rear passenger door =(

I am living in Malaysia and I was quoted RM 1200 which equivalent to USD 300 p/door. It is too costly to bare such repair as for the past 2 months ive encountered faulty cam gears and also steering lock! it costed me RM 10k = USD 2500

rob_fed

You only need to connect to the original 2 wires that go to the stock lock actuator/latch. The "reverse polarity" occurs with these two wires. For the rear doors, I've never taken off the door panel so I don't know if there is any "extra room" to place the aftermarket actuator.

danfranjr

hopefully it works.

danfranjr

Guys, if you are kind enough to circle where do I need to place the universal actuator and what is needed to cut from door panel?

Pictures attached. None of my workshop guys able to do so.

danfranjr

Pictures attached

nnkfws333

I am going to try this fix but I'm having a hard time trying to understand where the universal lock actuator will be clamped too if the original lock actuator stays in place. Does it screw into the aluminum cover? Can anyone help?

rob_fed

I started the original thread, yes, you can screw to the aluminum panel, but the actuator needs to be placed to the rear of the arm rest so the empty cavity on the door panel can cover it. The actuator push/pull rod needs to connect to the the factory push/pull rod that connects to the locking knob at the base of the window. If you bend the push correctly, you can connect to right under the black accordion shaped rubber grommet.

nnkfws333

Thanks for the fast response! From the pic posted, you danfranjr, you mean that horizontal black accordion shape grommet or the vertical one attached to the locking knob? When you say "bend the push" did you mean bend the rod? Lastly, if you screw the actuator to the aluminum frame, is it strong enough to keep steady? Im trying to attempt this without taking off the aluminum panel. Also I really appreciate the help!

rob_fed

Good point... vertical to the lock knob. Also, yes, the aluminum is plenty strong enough to anchor the actuator. If you are worried, use some epoxy putty between the actuator and panel to spread the mechanical load.

danfranjr

i have done both front and rear passenger door.

For the front, i noticed he took out the aluminium cover without any difficulties and placed the actuator side-by-side with the stock faulty actuator. Then close the aluminium cover using steel rivet (dont know how to call it), easy task. Does not require any inner part trimming of the plastic door panel. On the other side, if the actuator is placed outside of the aluminium part which is way below (7 o'clock) position, the rod is not long enough and rod bending is required to connect it to the door lock. Troublesome for the mechanic i guess from the way i suggested to them after reading from the posts above.

For the rear, it is the headache part where the actuator must be placed nicely as it requires a stronger push/pull of the door lock. it is different than the front because the rod goes left/right instead of up/down like the front door. This actuator is placed outside of the aluminium cover by screwing against the aluminium cover. you will be able to find the right spot once u have adjusted the correct position.
(This info is for rear door issue if encountered)

All-in-all, the cost of doing is USD 90 (both front and rear passenger door)

novalyx

Can anyone post step by step pics of how this is done? Would greatly appreciate it. My front passenger door lock knob doesn't seem to move at all when the button is pressed to open and close the door.

jimmyinoz

This solution will probably work on most MB doors.

I found it on this blog and decided to try out ROB_FED suggestion that it could be installed on the outside of the aluminium panel without drilling out and removing it first.

I made a simple mounting bracket so to get the alignment and stand-off position right. I used a plate with lots of holes so to provide some adjustment. Then secured the bracket to the aluminium door panel with self taping screws. I glued the 5/32 nuts that hold the generic actuator in the right position onto the back of the bracket, once I determined the correct positioning. Here is the template:




I also drilled out the plastic actuator mounting holes to 5/32 so I could use readily available nuts and bolts

I've shown on the photograph below the measurements for the actuator positioning that allowed it to operate without fouling and ensuring the cosmetic panel fitted back ok.



Taken from the two datum points : the 'aluminium rivet' and the door panel 'anchor nut' - the dimensions are as follows:

Red = 6.5cm Blue = 10cm (for top bolt)
Green = 12.5 cm and Black = 10.5 cm (for bottom bolt)

In the second photo I show the minimum amount of re-work needed to allow the actuator some clearance. I simply took my knife and cut away the small nylon reinforcing ribs in that area. The pencil marks showed where I calculated the actuator piston reached.


Fit the cosmetic panel back ensuring you route the door release cable through the guide. Check electrical connection are made and secure.

lucas avil

I was wondering if you can help me jimmyinoz and explain why you drilled the plastic rivets holding the actuator to replace with bolts.Also can you please link where you or your universal actuator from.Lastly I was wondering if the anti theft on the door still works with the aftermarket door lock actuator?

lucas avil

Sorry to bother you but i was wondering if you can help me jimmyinoz and explain why you drilled the plastic rivets holding the actuator to replace with bolts.Also can you please link where you or your universal actuator from.Lastly I was wondering if the anti theft on the door still works with the aftermarket door lock actuator?

jimmyinoz

You have misunderstood me!

I never drilled out the plastic rivets holding the existing actuator. I left it in place.

I drilled out the new actuator mounting holes to 5/32 dia so I could use more readily available bolts. ( I couldn't find smaller diameter bolts of the required length). Hope that clarifies.

I bought the actuator on eBay try this link https://www.ebay.com.au/sch/i.html?_...enoid&_sacat=0

Never tried the anti theft to see if it is affected.

lucas avil

Would you mind going to your car, sitting inside it then looking the door from your key.then pop the lock on the door u did this on and open it to see if the antitheft still works

p19343

Thank you for providing excellent information on this topic. Can you provide additional details on this step?.

>>"The actuator push/pull rod needs to connect to the the factory push/pull rod that connects to the locking knob at the base of the window. If you bend the push correctly, you can connect to right under the black accordion shaped rubber grommet." 09-02-2016, 08:42 PM<<

The Factory push/pull rod (blue flexible cable) connects to the factory actuator BEHIND the aluminum panel. How do I gain access to connect the two push/pull rods?

jimmyinoz

The new actuator needs to be slaved into the bottom of the indicator pin. You do this by removing the concertina shaped rubber grommet.

novalyx

Do you have a picture of how the wire metal attachment wire from the universal connector attaches to the original one?