The unit is actually a H25ct. The problem I am having is that when you get off the unit the engine won't thottle up and won't drive. The unit has the hydrostatic drive with a fwd and rev pedal. If the unit decides to throttle up it won't always kick into gear. It will drive sometimes and runs great until you get off unit or pull park brake. I know both brake switches are working and the seat switch is working. I have tried to play with relays but can't seem to find one that is for the trans. Has anyone ever had this problem or can someone help me locate a schmatic or book for this truck. Thank you