Fan 1 (Left Fan) - No Low Speed Fan Operation (P0480)

If only one fan does not have low speed operation it eliminates the PCM and control circuit, except for the portion of the harness between the splice and the PDC. If fan 1 is operating on high speed but not low speed, it indicates that the fuse, fused B+ circuit and radiator fan motor are likely good. An issue with any of these would cause the fan to not operate on high speed also.

1. Turn the ignition on. Using a 12-volt test light connected to ground, back probe the low speed fan control circuit at the PDC connector. Make sure to back probe the terminal for the radiator fan 1 relay control at the PDC. Radiator fan 1 (left) should run at low speed with the low speed control circuit grounded.
   1. If the fan runs at low speed with the control circuit grounded, it would indicate an open control circuit between the splice and the PDC. Isolate and diagnose the control circuit for an open or high resistance.
   2. If the fan does not operate with the control circuit grounded, continue to step 2.
2. Remove radiator fan relay 1 from the PDC. Load test the voltage supply at terminal 30 of the relay connector. Read the CIRCUIT LOAD TESTING PROCEDURE for information on building a simple load test tool and for additional load testing information and alternative methods of load testing or voltage drop testing a circuit. Refer to CIRCUIT LOAD TESTING PROCEDURES .

   Courtesy of CHRYSLER GROUP, LLC

   NOTE:

   A way to verify that there is no resistance in the circuit being tested is to perform a simple voltage drop test across the 3156 bulb of the load test tool. The voltage drop across the bulb should be equal to the voltage reading across the Battery terminals if there is no resistance in the circuit being tested.

   1. If the bulb is illuminated and bright, continue to step 3.
   2. If the bulb is not illuminated and bright, replace the PDC in accordance with the service information.
3. Connect a fused jumper between terminal 30 and terminal 87 at the radiator fan relay 1 connector in the PDC. Cooling fan 1 should operate at low speed with the jumper in place.
   1. If the fan operates with the jumper in place, replace the relay and retest.
   2. If the fan does not operate, continue to step 4.
4. With the jumper in place, back probe and measure the voltage on the radiator fan relay 1 output circuit at the PDC connector. Battery voltage should be present.
   1. If battery voltage is not present, replace the PDC in accordance with the Service Information.
   2. If battery voltage is present, continue to step 5.
5. Back probe and measure the voltage on the radiator fan relay 1 output circuit (A212) at the radiator fan resistor connector. Battery voltage should be present.
   1. If battery voltage is not present, repair the circuit for an open or high resistance.
   2. If battery voltage is present, continue to step 6.
6. Back probe and measure the voltage on the radiator fan relay 1 output circuit (N23) at the radiator fan resistor connector. The voltage will not be equal to battery voltage but there should be voltage present.
   1. If voltage is not present, replace the resistor and retest.
   2. If voltage is present, repair the (N23) circuit for an open or high resistance between the resistor and harness splice.