Need help with wipers - I have replaced the switch twice and after a few months the wipers won't shut off again - the MB dealer keeps telling me the switch is bad but I hessitate to put another in - any ideas as to why the switch is failing?

wiper moter has too much amperage draw causind the switch to fail.......have it tested.

Thank you I will give that a try --- However strange this must sound if I shut off the headlights the wipers would stop - I found a broken parking bulb - replaced it and so far it is working good - but i will still take the motor off and make sure --- Thanks again:)