Cooling System: Testing and Inspection
SYSTEM DIAGNOSIS AND TESTINGFig. 4 Electric Cooling Fan Wiring Diagram:
Fig. 5 Electric Cooling Fan Wiring Diagram:
Fig. 6 Electric Cooling Fan Wiring Diagram:
Fig. 7 Electric Cooling Fan Wiring Diagram:
1. Test electric cooling fan motor as described under Component Diagnosis & Testing. Component Diagnosis & TestingIf motor does not operate satisfactorily, repair as directed. If motor operates, continue with procedure.
2. Ensure ignition switch is in Off position, then check for battery voltage at fan relay connector terminal 1. If battery voltage is present, continue with procedure; if not, proceed as follows:
a. Inspect cartridge fuse in power distribution center and replace as necessary. The power distribution center is located at the lefthand front corner of the engine compartment.
b. Inspect circuit C26 for an open or a short to ground and repair as necessary. Refer to wiring diagrams in this section for circuit identification.
3. Connect a 14-gauge jumper wire between fan relay connector terminals B and D. If fan operates, continue with procedure; if not, inspect circuit C25 (between fan relay connector terminal D and fan motor connector) for an open or short to ground and repair as necessary.
4. Start engine and run until normal operating temperature is reached, then inspect connectors in circuits C9, C25 and C26 for proper connection and repair as necessary.
5. If motor remains inoperative, connect a DRB scan tool to engine compartment diagnostic connector, located near the righthand rear corner of the engine compartment.
6. Follow DRB user's instructions to access PCM diagnostic trouble codes. If no diagnostic trouble codes are present, perform visual inspection of all electrical components once again and repair as necessary; if DRB displays "Radiator Fan Relay Circuit," continue with procedure.
7. Place ignition switch in Run position and check for battery voltage at fan relay connection to circuit C26. If voltage is not satisfactory 0-1 volt), continue with procedure; if voltage is satisfactory, proceed as follows:
a. Place ignition switch in Off position and disconnect 60-way connector at PCM, then place ignition switch in On position.
b. Check for battery voltage at 60-way connector cavity 31; if correct voltage is present, replace PCM. If not, repair open or short in circuit C27.
8. Place ignition switch in Off position and disconnect 60-way connector at PCM, then check for battery voltage at fan relay connection to circuit C26. If correct voltage is present, replace PCM; if not, continue with procedure.
9. Place ignition switch in On position, then test for battery voltage at fan relay connection to circuit C27. If correct voltage is present, replace fan relay; if not (voltage is 0), repair open or short in circuit C27.
10. Place ignition switch in Off position and connect PCM 60-way connector, then ensure system operates properly.