Decelerator or Hand Throttle (STD cab) Position potentiometer voltage is too low
High range clutch is not calibrated
Aux 3rd Lower solenoid failed open or short circuit.
Low pressure switch (-) input shorted to power
Foot Throttle Position potentiometer voltage is too low (engine controller pin B30)
High range clutch is not calibrated
3-point Hitch Fails To Lift,Low oil level.Worn hydraulic pump.Rate of drop valve closed.Excessive load on hitch.Hydraulic oil too cold.Hydraulic oil suction filter plugged.