I have a 2000 C280 and the wiper stopped working. Unlike most wiper issues, the wiper did not have a bonding problem, get stuck, or have others issues until my wife tried to use them and the wipers would not work. All functions on the combi switch work except the wiper. The fuses are all ok.


Attached is a picture of my attempt to diagnose the problem. Blue connector in the middle of the picture comes from the wiper motor through the yellow, green, red, and brown wires. When connected, the blue connector plugs in to the area behind the fuse box where the relays are.


In the picture, the red wires are plugged into the blue connector on one side and (through the alligator clamps) connected to the corresponding plug on the board where the relays are.


Before doing this, with the blue plug disconnected, there was 12V power to the no.1 plug (where the yellow wire would connect) when the car was on - none of the other plugs were hot. Changing the position of the combi switch had no effect on which plug had power and the no. 1 plug never lost power.


As shown in the picture, when all plugs in the blue connector where connected to the relay area through the alligator clips, there was no power to any of the 4 circuits - including the no. 1 circuit (yellow). When the no. 4 circuit was disconnected (brown), there was power to the Nos. 1, 2,and 3 circuits (Y,G, R). Changing the position of the combi switch has no effect on the above.


It seems to me that the problem could be: 1) motor, 2) combi switch, or 3) n10/1. I don't want to change the combi switch unless I am certain its the problem. I can easily replace the motor and/or the n10/1 but hate to just throw parts at the problem unless I have to.


You should know that the car was overheating (fan would not come on)and I fitted it by replacing the fan relay in the drivers side fender. I do not think the problems are related but the wiper problem arose immediately after the relay replacement.


Your thoughts are appreciated.


Thanks

 

I am told that it is almost always the switch unless anyone else has an idea. My trouble shooting does not seem to have helped. We shall see.

 

Nick, if I were you, I'd get the local garage/shop to diagnose what's wrong. Maybe it will show up on the fault codes? I'm generally OK tackling mechanical problems, but usually get in a mess over electrical ones and once wasted money on replacing a perfectly good MAF when the problem (cutting out) turned out to be a faulty sensor (subsequently diagnosed and fixed fast and not expensively by my local garage). Sorry to be defeatist. Maybe someone else has better suggestions? Good luck, John

 

So far, I have replaced the combi switch. When that did not work, I bought a new motor and plugged it in - that did not work either. I am about to give up, fall on my sword, and bring it to the dealer/indie garage as suggested above. I hate doing that. Any other ideas?


Your thoughts are appreciated.