High range clutch solenoid or its wiring failed open or shorted to ground
Aux 4th remote valve LEVER potentiometer is failed in the Armrest Controller
Cab sensor open or shorted to power
Engine Controller Failure - Hardware Failure
High range clutch solenoid or its wiring failed open or shorted to ground
If Inadequate air flow is problematic, so clogged air filters, evaporator core air flow restricted, faulty blower fan motors, defective blower switch or faulty wiring or loose connections.