Either your switches are out of sequence or the actuator arm might be causing the issue or maybe the bushings in the tiller arm. Have you removed the two switches and tester for continuity while opening and closing them? You might want to trace the wires from switches to controller while moving the handle like your turning it from left to right to duplicate operator use. When does it trip out? Is it when your driving, lifting or lifting while driving. Try to get specific info. from the driver.