How to test cabrio microswitches?
Thread Starter
Newbie
Joined: Sep 2022
Posts: 2
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1999 CLK 320
How to test cabrio microswitches?
I've been reading through the forums and they've been super helpful, but one thing I keep seeing mentioned and I don't know how to do it figuring out which microswitch for the convertible top function might be bad. I'm assuming there's a list of them somewhere, with are they supposed to be open or closed when the switch is pressed, but I haven't been able to find it. Is it just as easy as pulling the switch and checking continuity with it pressed and then not?
For reference, I have a '99 CLK 320 - convertible top won’t go down. Worked fine two days ago. Spent the better part of yesterday swapping out some corroded ABS sensors and fixing a windshield washer nozzle problem. Decided to take it for a test drive last night but when I went to put the top down I got nowhere.
Pushed overhead button and twisted release handle to unlock front of top - windows all went all the way down and dash light blinks like it’s supposed to.
Pull up on top button to open - solid red for a second then starts blinking (the slow blink, not the fast one). No sound from pump/motor. No other warning lights or issues and none of my local shops have the fancy MB code reader.
Have checked fuses and relays, fluid level is good. Rollbar/headrests are in fully lowered condition (and their operation by button works as normal). Have cleaned the luggage cover switch and made sure it’s in the correct position.
Pulled the battery and had tested by the shop, it’s good to go. Put the car on MB v2.0 scanner, no codes related to the top functions. Have tried pulling the battery to reset the system. Have manually lowered and raised the top to let switches “relearn” (am I supposed to do that with the car running?) and I’m still not anywhere closer to where I was before.
I can’t figure out how an ABS sensor and a windshield wiper could kill my top function, but here I am. Thanks!
For reference, I have a '99 CLK 320 - convertible top won’t go down. Worked fine two days ago. Spent the better part of yesterday swapping out some corroded ABS sensors and fixing a windshield washer nozzle problem. Decided to take it for a test drive last night but when I went to put the top down I got nowhere.
Pushed overhead button and twisted release handle to unlock front of top - windows all went all the way down and dash light blinks like it’s supposed to.
Pull up on top button to open - solid red for a second then starts blinking (the slow blink, not the fast one). No sound from pump/motor. No other warning lights or issues and none of my local shops have the fancy MB code reader.
Have checked fuses and relays, fluid level is good. Rollbar/headrests are in fully lowered condition (and their operation by button works as normal). Have cleaned the luggage cover switch and made sure it’s in the correct position.
Pulled the battery and had tested by the shop, it’s good to go. Put the car on MB v2.0 scanner, no codes related to the top functions. Have tried pulling the battery to reset the system. Have manually lowered and raised the top to let switches “relearn” (am I supposed to do that with the car running?) and I’m still not anywhere closer to where I was before.
I can’t figure out how an ABS sensor and a windshield wiper could kill my top function, but here I am. Thanks!
Newbie
Joined: Oct 2023
Posts: 2
Likes: 0
CLK 200K cabriolet 2001
Yesterday I reached the pump in the trunk and switched the relay with the one for the fuel pump.
Miracle - it worked. It seems that the relay was "stuck" or there was a bad connection.
