2003 CLK (W209) - Electrical mistery (front headrests, sunroof, windshield and headlights washers)


Feb 6, 2019
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Your Mercedes
2003 CLK 500
I recently bought a CLK 500. Runs good but there are some electrical (I think) problems.

1) First problem is that my front headrests don't work. Both of them, which is weird. When I press the button on the door panel I hear a click and the headrest goes down or up a couple of mm. When I fold the seat, headrests go down and back up normally but moving them with the button does almost nothing.
Here is a video:
Also, on the passenger side, the seat's rear part height adjustment doesn't work. Front part works. Only rear part of the seat doesn't move up nor down (forward and backwards works good).

2) The second problem I have involves the sunroof. It doesn't roll open. However it does tilt up and seals back down (with a not-healthy sound, I'll post a video tomorrow). I tried resetting it by holding the buttons for 5 seconds in each direction, in correct order but it didn't help. I suspect there is a broken mechanism or something.

3a) Third wierd thing. My windshield washers squirt only for the third press of the button. It goes always like this:
1st push - washers squirted a tiny ammount of fluid
2nd push - this time no squirt
3rd push - washers squirt until I release the button
Doesn't matter how long I hold the button pressed, I have to press it 3 times and only then I get a proper squirt.

3b) I think it may be related to my headlight washers not working at all. I have two purple/pink tubes under the bonnet. One on each side. They go from somewhere near the firewall and end near the headlamps. Aren't connected to anything. I saw on the Internet that they are connected to a non xenon headlamp.
Here you can see the pink tube connected to the white circle on the top of the photo (which is a bottom of the headlamp) https://ibb.co/SmmZT9s
The wierdest thing is when I press the button to wash the headlamps, the engine slightly drops its' RPMs. Will post a video tomorrow.

4) Finally, sometimes under hard acceleration my headlights dim for a fraction of a second.

I really hope to get some help from you :) cheers!


Senior Member
May 30, 2007
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Your Mercedes
SLC300 - C250d Estate 4 Matic & Z900rs
The wierdest thing is when I press the button to wash the headlamps, the engine slightly drops its' RPMs. Will post a video tomorrow.

New pump required, less than £20 on ebay.

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