2009 c300 windshield washer will not turn off even with key off!!

Question by jamessmith posted 3 months 3 weeks ago in 2008-____ (W204)

a have 2009,  C300 this week, the windshield washer pump came on.  it will not turn off even after I stop the car, turn off the engine and take out the key,  only by disconnecting the battery will it turn off.  it will come back on when i re-connect the battery??  i disconnected it to get it to turn off?