I am hoping someone else has run in to this and can tell me what the issue is. 2003 C230 Coupe - new to me. Turn signals will not seem to engage correctly, normal use they will only engage far enough to blink 3 times in the passing mode. If I hold the switch collar on the column (it seems a bit loose on the column, rotates when I push on the switches, I can get the left signal to engage normally. The right switch will only stay on if I hold the stalk in the right engage position and do not release it. Has anyone else had this? Do I need to just replace the switch assembly?

Not sure if there's a loose connection in your turn signal stalk assembly, but before worry about that, you may want to first open up your steering column assembly and fix the loose collar that is allowing the entire assembly to rotate. Common problem with W203.

Fix rotating/loose steering column Personally I used Gorilla Glue, but some people also used set screw or similar fastener. I actually recommend the glue method. Just make sure the column is set exactly where you want it to be before that glue dries.

Steering column disassembly

Do you have the problem where the turn signal stalk no longer holds in place for continuous blinking?

Most likely you will need to replace the combination switch. It requires removing the airbag, steering wheel, and clockspring/steering angle sensor. It's not a horrible job, but some people get nervoice working around airbags.

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I have had to replace the combination switch twice over the years as it would not stick to the right. Maybe I should just stop using the blinker instead like most drivers here in FL... The only difficulty I have had was in removing the large Torx bolt in the middle of the steering wheel. It was hard to counter hold the steering wheel, and I was worried about breaking the steering lock. I believe MB has a special tool to hold the steering wheel in place.

I have heard other mention the problems with loosening the steering wheel bolt. I've doen a few MBZ cars and never had a problem. in fact, I was surprised at how little torque was on it. The spec is 80Nm, ( 60 lb. ft.) which is really not that much. It only needs to not come loose since the wheel is on a spline shaft, so it can't spin.

I had to replace the combo switch when the wiper pump switch stopped working.

The steering wheel Torx bolt defied all efforts to loosen. I tried long breaker bar, a pneumatic 1/2 impact, tapping on the nut, etc. I was about to give up when I made a run to Harbor Freight. I bought the Earthquake XT 1/2 cordless impact on sale. Best $169 I ever spent.

It blew the bolt off without pause.

The impact has the advantage of not putting much turning force on the wheel.
5

It is actually 2 small specially shaped plastic pieces in side the combo switch that gets worn out and does not hold the stick in place.
I could not find any one selling those pieces as parts even though I had dismantled the mechanism. Ended up changing the whole combo switch. Still keeping the old switch in case someone knows where to source these plastic parts.

Look at these videos from Youtube.

and

Wonder if any 3-D printer guys can make these plastic parts?

Does anyone know if there is an (another) updated PN? I had the original turn signal switch replaced under warranty at the 4 year mark (2007) with PN 000-545-23-10. This one lasted 9 years (2016) before the same problem reappeared.

Photos are of the worn replacement switch. In my case, the wear was in both the white plastic pieces (the notch in the hole was worn down) as well as the black "flaps" (a round cylindrical tab that engages the notch had worn down). See photos. One of the black pieces has been removed and is in the wrong place in the 1st photo.

I agree it is awfully silly to have to replace an entire switch over 4 small plastic parts. These days I've just learned to hold the stalk as required in the up/down positions. At least the stalk still stays in the neutral position.



Worn plastic parts

Worn notch

Does anybody sell these parts, e-Bay?