Engine Position Sensor (8.3, 9 Liter) or Crankshaft Sensor (15 Liter) is failed
Mid range clutch solenoid coil or its wiring shorted to power
Temperature select pot open/shorted to power
Engine Position Sensor signal is failed (no signal at engine controller pin A9)
Mid range clutch solenoid coil or its wiring shorted to power
If Air conditioning does not work,possible causes are blown fuse, faulty wiring or loose connections, fxan belt loose or slipping or defective switch or defective compressor clutch.