W204 2011 c250 cdi windscreen wiper not working

[Pritu79]

Hi,
My w204 wiper isn’t working, obd says not communicating with the motor…. Its been a while since i have driven it approximately 6 months, As I couldn’t find time to repair the wiper or rather i don’t have a clue how to test it..
I Removed the wiper assembly in the morning, it has 3 wires, 2 of them have constant supply.
Would really appreciate it if some one could shed some light on testing the motor out side the car.
If the motor is working I could look some where else.

 

[geoffus]

There should be, a positive 12v on the red, negative 0v on the brown and the other wire is the trigger 12v positive ( maybe pink/grey ) that signals the motor to start.
It could also be the bonnet switch that cuts power when its open.