C250 TD Windscreen wiper erratic function

[geoff1937]

Front wiper bhaves erratically. On occasions wiper initialises on engine start up, runs for a period and then stops. At other times wioper does not follow switch command ie intermittant is continuous before stopping, wash wipe the same. Had wiper motor and gearbox replaced 12 months ago (at main dealer) fault started immediately after this. Reported to dealership - apparently they could not replicate behaviour although it continued to have this erratic behaviour ever since. Have reported it again. Dealer's opinion is that it is nothing to do with the replacement of parts but is a sensor/ transmiter fault. Help please

 

[Dec]

Hi Geoff, as the motor is nearly new it is reasonable to assume that it is not the cause, the likelihood is that the fault is with the relay, number 2 in picture or to a lesser extent the stalk switch.

You could dismantle the stalk to investigate, drive the car for a while with it dismantled, using the Peg to control the wiper functions. If that doesn’t yield any results you should turn your attention to the relay.

Dec