I had already checked the switch, wires, grounds, fuses, circuit 15 and 30 power nine ways to Sunday with my multimeter. I am a BMW and Mercedes Tech, I just didn't have actual wiring diagrams or function descriptions so I had to go with wire colors and instinct. I took the cover off of the flasher to determine how it worked and saw a circuit board. Since it was not in an easily accessible place I didn't want to disassemble a friends truck to check it so I bought a new one from the dealer and it got better. Thanks again.