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8692 Views 6 Replies 6 Participants Last post by  Skylaw
yesterday i was driving and it was raining. the wipers were working perfectly and i had them on i(auto position). suddely they stopped working half way a complete oscilation. it was raining big time i actually pulled over turned them off and on nothing happened. i then pressed the windshield water spray button and the wipers worked. i drove for 2 hours no problem. this morning same thing happened, this time i turned the wipers off and when i turned them on they worked. any one ever had this problem. s500 2005.
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It has happened to me. I have made many posts on here. No definitive solution or answer to the issue.
It has happened to me. I have made many posts on here. No definitive solution or answer to the issue.
Same here. Same year and exact car by the way.....
Same here

This happens to me about every six months. :confused:
since no one knows, i guess MB has to call back our cars for this, lol
There are two contacts in the wiper motor that touch two circular rails on the large wiper gear.
There is a gap that when one of the contacts hits, cuts power to the wiper motor, if there is no power coming from the switch, this is how the motor knows where to park.
If there is any dirt or excessive wear to the contacts or the tracks, then there is no power if the switch is off.
However, I am guessing that when on auto, the rain sensor flicks the wipers and then cuts the switch power, and does this instead of feeding continuous power.
I had this since I bought my S55, but last week I took the wiper mech out and cleaned the contacts, and it cured the fault completely.
Its not a difficult job, all you need to do is remove the wipers, (Turn them on, then turn off the ignition when they are at the end of the wiper stroke and remove the nuts). Remove the water proof trim (4(?) fixers under the hood, and very carefully prise the trim out of the retaining strip by levering it up CAREFULLY against the screen with a wide flat blade tool).
Remove the mechanism retaining nuts and bolts. There is a round black plastic nut type thing at the front which will turn freely when the nut is removed, mark this so that it is in the same position when the mech is put back in, as this thing alters the angle of the blades to the screen.
Take out the electrics plug and pull out the wiper assembly.
Look where the motor is, there is a plastic plate on the gearbox which is held on by clips built in, prise them off and take off the plate, I think there was a clip for the wiring as well.
You will see the contacts and the rails, I just wiped out the excessive grease and smeared it back on the gear, then cleaned up the contacts and tracks with 2500 grit paper.
Expect to crack the water proof trim, as the groove it sits in gets gunged up over the years, I was lucky as the previous owner had the screen replaced and the trim came out complete.
Just reverse everything to build it back up again, remember to put that angle adjuster back in the same place.
I have typed all that from memory, so if I have missed anything then just use common sense.
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Thanks, astroscan!
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