At first i thought the wiper stalk saw going bad. But if i get into the truck, turn the key to run without starting the wipers will function fine. All speeds and the sprayer function work perfect. Once the engine get started the wipers no longer work. Everything else on the stalk (high beams, turn signals) works as it should whether the engine is on or off. Before starting the truck one day i turned the wipers on and then started the truck while the wipers were moving. They completed their path to the bottom of the windshield and then stopped moving. Fuses and everything are fine and the wiper motor works since it works with the engine off. Could this be a grounding issue?

 

I would guess ground issue.