Pontiac Repair: Rear window wipers not working

Question
I have a 98 Pontiac Gran Transport van and the rear wiper does not work. The defroster works, but when I turn on the wiper button, there is nothing moving.  

Is this something I need to go to my old dealership to fix? Is it a fuse or something else? The guy who does basic work on my car doesn't know what to do.

Answer
Hi Mary:

well with out seeing it I have no idea what's wrong with it either but my Guess would be a wiper motor it's self that is bad usually the shaft corrodes to the housing that the motor sits in and that is why the motor doesn't work. BUT it could have a blown fuse (doubt that) or a broken wire in the pass though between the body and the lift gate. the trim has to come all off and check to see if the motor has power and ground to it when the switch is turned on.