I have a 1998 chevy s-10 and am having problems with the winshield wipers. Some times they work and sometimes they don't. When they don't work I hear what I think is the motor trying to move them but they don't move. If I wait for 20 or 30 minutes they work fine. Anyone experience this before? Not sure what other info is needed but any help is appreciated. Thanks in advance, ultradennis