Mercedes-Benz Forum banner

1 - 7 of 7 Posts

·
Registered
1997 Mercedes Benz C280
Joined
·
8 Posts
Discussion Starter #1
I have a 1997 C280 and the windshield wipers don't work. I just bought the car and it came with the problem.

When you turn the switch on, absolutely nothing happens. The motor doesn't hum or attempt to engage. There is, however, a clicking sound from the Relay, however, no movement from the motor.

I bypassed the Relay and made the motor spin and it works perfectly fine. Today I got a different combination relay from another C280 and replaced it but that did not fix the problem either. The fuse is a 40amp fuse and it works fine.

The switch inside the car operates the blinkers, low/bright lights, windshield wipers, and the windshield wiper pump for the jets. EVERYTHING works perfectly except for the windshield wipers.

I tested the voltage coming out of the fuse box and going to the motor a there is 12V present, however, it is only on one terminal and it doesn't change when you turn the switch inside the car. I turned the switch to positions "1," "2," and "3," and no voltage flowed to any of the other prongs/terminals on the wiring.

I am out of ideas and I am not sure what the problem could be. Is there any other component that I am missing that could be potentially wrong, besides the switch (inside the car), the combination relay, the fuse, and the motor?

The switch inside the car could be bad, but when I turn it on I hear a clicking in the relay, so that makes me think that it is actually passing a signal.

PLEASE, any insight would be greatly appreciated.
 

·
Registered
1962 W111 220SE Coupe
Joined
·
2,289 Posts
It is not unheard of for the combination switch (the stalk) to have only one function fail, but your are right that this seems unrealistic given that the relay is clicking. May I ask if the relay you substituted was from a friend's car or from a salvage yard? If you did not witness the relay working, or have someone who can confirm, then assuming it functions may be the problem. It's possible both relays are bad. Forgive me if you addressed this specifically.
 

·
Registered
1997 Mercedes Benz C280
Joined
·
8 Posts
Discussion Starter #4
The relay I replaced it with was working; it was from a dealer car. Tomorrow I'm going to try and isolate where the problem is at by testing voltage indications at different places. It's the only thing I can think of to narrow down where the issue is. Do you know of any good way to test the combination switch?
 

·
Registered
1962 W111 220SE Coupe
Joined
·
2,289 Posts

·
Registered
Joined
·
2 Posts
Han the same problem with my C200. The relay clicked, and that was it. I nudged the relay side ro side and everything went into action. So my solution was to mount a little rubber to the side of the relay to keep it tight in the slot and everything works fine.
 

·
Registered
1995 C220
Joined
·
2,800 Posts
If it is a wiring problem you should be able to pull the relay out and jumper 12 volts to one of the terminals and make the motor work. If it doesnt, then I would suspect the mechanism is froze up and needs to be lubed. You said the relay clicks, so the switch must be working inside the car.
 
1 - 7 of 7 Posts
Top