How to: Extend the life of your Keyless Go/Repair Keyless go handles




Even used ones (that might still break) are going for over $140. All right, I thought, I wonder if I can repair the handles.Here is a picture of a typical handle, with lock and unlock (Borrowed this picture).

What appears to happen is that the rubber membrane surrounding the switches cracks over time allowing water to get in and damage the components. On my driver door handle, is was well cracked on the underside. and deep into the crevice:

I opened it up and saw two wires and a microswitch inside it:

The pair of wires are joined to two microswitches in parallel - one for lock and one for unlock. To distinguish between a lock and an unlock signal, when you press the lock button, it puts a 475 Ohm resistance across the wires. For an unlock, t puts a 300 Ohm resistance.
My plan is to drill two holes in the plastic and insert water proof microswitches (one for lock and one for unlock) as shown below:
I am looking for the appropriate switches right now .. identified a couple that might work .. solder the appropriate resistors in and voila. Not stock but will be functional again. The reason I put two switches on the inside of the handle is that:
a. It is easier to get to. The switch on the outside is routed through solid plastic.
b. It is not as cosmetically noticeable if you screw up.

For the other door handles that were still operational, I decided to inspect them and found some were starting to wear a little with a slight crack.
I decided to mask off the area around the black rubber, clean the groove really good with alcohol there was a lot of gunk in there which could be another reason why they break - due to abrasion. Then added Permatex Ultra black in the groove:

Here is the completed handle .. it is not perfect but once mounted on the door, you can't see the imperfections at all:

This should keep the gunk out of the groove and (hopefully) extend the life of the handle.. There may be better products out there than the Permatex Ultra, that is just something, I had on hand and was fairly pliable .. maybe a Silicone would be better? I have no idea. Anyway, hope this is useful to someone.
I will post back once I get the switches and fit them I already tried the resistors and the keyless does function correctly.
Last edited by turbo97se; Jan 24, 2016 at 11:35 PM.




I decided to look past page one just now since I just noticed there are like 7 pages of info ... looks like someone else tried to pull one apart but did not repair it.
I was going to wait until I was all done, but a lot of you guys are pretty smart, I thought I would see if anyone could recommend a good small waterproof microswitch. I bought a couple of different types online from Ebay. We will see if they work. The microswitches are like a couple of bucks with shipping. Beats the over $280 from the Mercedes. It would have been nice to replace with capacitive touch sensors like the W212s, but that is too much work I think ... definitely doable and would be cool .. I'll let someone else take that one on.
https://mbworld.org/forums/w211-amg/...ement-diy.html
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http://huskerparts.com/2005-mercedes...11709960-item/
I think some colors are cheaper than others. The real problem to fixing it is finding a micro switch that will work. I think someone mentioned in another thread about taking one from an old fax machine, but that's kinda hard to source parts like that. I had 3 of mine replaced when I bought the car and one of them didn't last more than a year before it went again. At least MB has a 1 year and 12k warranty on their work.
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You have to get rid of the original microswitch in the handle to make room for unlock switch. There is no way to repair the one already there as it is embedded into rubber.
I used the Silicone gasket maker to seal the handle back up and "over molded" the handle and buttons together. This allows the black portion of the handle to still flex and press the unlock switch.

Drilled a hole in the plastic black piece of the handle

Black piece installed back on the handle. You can see the microswitch.

Added lock switch on the other end:

Added red rubber caps to the switches that protrude slightly above hole. I forgot to take a picture of them installed into the handle, here is what they look like:

Added gasket sealer:

Remove masking before the sealer completely dries. I will probably add another layer and smooth is out more. I tried Plastidip on the outside and cosmetically it looked better, but it peeled off easily. Probably because I was spraying on to Silicone:

Anyway, the handle is fully operational again. It's not super pretty, but you can't see it since it faces the door.
Last edited by turbo97se; Jan 31, 2016 at 12:31 AM.
Awesome work turbo
This really should be stickied along with the link on how to remove the handles. I'm willing to bet 99% of us will have this problem at some point in time.
Last edited by romeomikehotel; Jan 31, 2016 at 12:36 PM.




Here are a couple of videos:
Testing before install:
After install:
http://www.jameco.com/webapp/wcs/sto...0001_119011_-1
http://www.jameco.com/webapp/wcs/sto...0001_153252_-1




I got impatient and did not wait for my eBay switches to arrive. I just went to an electronics store close by work and picked some up. They don't have a brand or part number unfortunately.
I like the feel of my handle now .. it is has a nice rubbery grip and feel to it now.

Last edited by Deividas; Jul 20, 2018 at 03:35 PM.




How do I fix it? Should I take the door panel off? If I should remove the door panel, how will I glue that black foam thing back on the door?







