Why did my wipers on my 2006 H3 Hummer quit? - 2006 Hummer H3

This is a complex wiper circuit ! The place to start would be to check for DTC'S - diagnostic trouble code's .
DTC B3715, B3716, B3717, B3718, or B3719
The body control module (BCM) controls and monitors the state of the ON/OFF wiper relay control circuit. When the windshield wiper switch is placed in to a low speed setting, a signal is applied to the BCM. The BCM then applies battery positive voltage to the coil side of the ON/OFF WPR relay through the relay control circuit. This energizes the relay, allowing battery positive voltage from the FRT/WPR fuse through the switched side of the ON/OFF WPR relay through the HI/LOW WPR relay and to the windshield wiper motor. Ground is applied at all times to the coil sides of the wiper relays and the windshield wiper motor from G105.
• DTC B3717, the BCM detects a low voltage level on the supply circuit of the wiper micro relay for 1 second when the relay is energized.
• DTC B3718, the BCM detects a high voltage level on the supply circuit of the wiper micro relay for 1 second when the relay is de-energized
Your best bet mite be to take your vehicle to a qualified repair shop !