I have thought the same thing as well. The seat is an aftermarket Grammer B12 with that unusual swing arm OPS actuator. See video: https://www.youtube.com/watch?v=IuxpLL17xrc. Most recently the operator tells me that he places the directional selector back in neutral and steps on the brake pedal (which may change his position on the seat). After that he places the directional selector in forward or reverse and it begins working again. Trouble is... I have attempted this many times without the same results. You can manually operate the switch and hear the steer pump motor spool up although travel is still inoperative. Cycling the key does not seem to make a difference either. I am going to visit this customer tomorrow and spend some more time on it. Seat, switch and wiring have good integrity. Nevertheless I will be looking at them again closely.