98 GMC K1500 - wipers will quit randomly, usually late at night in a downpour on some busy highway or a backroad in the dead of night, and the motor/control panel under hood gives off a light buzzing noise. At first I could just give the wipers a wiggle and they'd start up again. Now I have resorted to going under the hood and wiggling the wiring harness at the wiper motor to get them to kick in. Seems to be getting worse and worse. When they do come on they're fine. I took it apart and cleaned the connections but they looked fine. There was a ton of red grease on the round ring thing that the relay points ride on but it was clean. I'm doubting it's the motor itself - maybe the control module?? Or delay circuit thing. Anyone else ran into this problem?