On vehicles with intermittent windshield wipers, the wiper motor circuit board may fail and cause the wipers to stop working at times. Replacing the circuit board should resolve the issue. Some vehicles were recalled for this problem and some were not. You will need to check with your local dealer to find out if a specific vehicle was included.Google+
Car Problem Reports
GMC Envoy Failed Wiper Motor Circuit Board May Cause Intermittent Wipers to Stop Working
GMC Envoy Problem
Average Mileage: 152,667 mi (69,001 mi - 199,000 mi)
THE WIPERS STOPPED AND THEN STARTED. NOW HAVE COMPLETELY STOPPED. THIS IS CRAZINESS. AND ITS NOT THE MOTOR OR THE SWITCH.
TRYING TO FIGURE HOW MUCH IT IS TO GET THIS REPLACED OR FIXED. UGGGH
The wippers abrupty came on full fast & now will not turn off or even move to a slower setting, The GMC dealer in town said it needed a new curcuit board & it will take a few days. looked up the recalls & found they had this issue with 2002 & 2003 GMC vehicles what was changed to ensure I don't have same problem.