The windshield wipers may not work intermittently due to a faulty wiper motor control board. Our technicians tell us that lightly taping on the wiper motor when the fault occurs should temporarily get the wipers working again. 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 Yukon Denali Windshield Wipers May Fail Due to Faulty Wiper Motor Control Board
GMC Yukon Denali Problem
Visitor, 2000 GMC Yukon Denali
Wipers only work on highest speed and you have to manually put them at the bottom of windshield when you turn them off.
Visitor, 1999 GMC Yukon Denali, 98,000 mi
My windshield wipers quit working from time to time. You can hear a noise from the wiper motor area like it is trying to work, but will not. Moving the wires into the wiper motor control board sometimes will get them working, but only for a short time. I replaced the wiper motor control board and so far, no more problems.