Test NTC-11: Checking Radiator Fan Operation
NOTE:
For circuit identification, see WIRING DIAGRAMS article. After each repair procedure has been completed, reconnect all components. Perform TEST VER-2 to ensure system is functioning properly. Ensure no DTCs are present before performing this test.
- Turn ignition on. Using scan tool, actuate low speed radiator fan relay. Observe radiator fan. If radiator fan actuated, turn ignition off and go to step 8. If radiator fan did not actuate, go to next step.
- Ensure low speed radiator fan relay is still actuated. Using a 12-volt test light connected to ground, backprobe terminal No. 3 (Dark Green wire) at radiator fan motor harness connector. See Fig 1. If test light blinks on and off, go to next step. If test light does not blink on and off, go to step 5.
- Turn ignition off. Disconnect radiator fan motor connector. Measure resistance between ground and terminal No. 1 (Black wire) at radiator fan motor harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black wire between radiator fan motor and ground. Ground is located near right horn.
- At this time, radiator fan motor is assumed to be defective. Replace radiator fan motor.
- Turn ignition off. Locate Power Distribution Center (PDC) on left side of engine compartment. See Figure. Remove low speed radiator fan relay from PDC. See Figure. Using a test light connected to ground, probe terminal "B" (Gray wire) at low speed radiator fan relay socket in PDC. If test light illuminates, go to next step. If test light does not illuminate, check for open in Gray wire between low speed radiator fan relay and fuse "E" (40-amp) in PDC. Repair wiring as necessary. Also check fuse "E". Replace fuse as necessary.
- Measure resistance of Dark Green wire between terminal No. 3 at radiator fan motor harness connector and terminal "D" at low speed radiator fan relay socket in PDC. See Figure and Fig 1 . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Dark Green wire.
- At this time, low speed radiator fan relay is assumed to be defective. Replace low speed radiator fan relay.
- Turn ignition on. Using scan tool, actuate high speed radiator fan relay. Observe radiator fan. If radiator fan actuated, no problem is indicated at this time. Test is complete. If radiator fan did not actuate, go to next step.
- Ensure high speed radiator fan relay is still actuated. Using a test light connected to ground, backprobe terminal No. 4 (Yellow wire) at radiator fan motor harness connector. See Fig 1. If test light blinks on and off, go to next step. If test light does not blink on and off, go to step 12.
- Turn ignition off. Disconnect radiator fan motor connector. Measure resistance between ground and terminal No. 2 (Black wire) at radiator fan motor harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black wire between radiator fan motor and ground. Ground is located near right horn.
- At this time, radiator fan motor is assumed to be defective. Replace radiator fan motor.
- Turn ignition off. Locate Power Distribution Center (PDC) on left side of engine compartment. See Figure. Remove high speed radiator fan relay from PDC. See Figure. Using a test light connected to ground, probe terminal "B" (Red/Brown wire) at high speed radiator fan relay socket in PDC. If test light illuminates, go to next step. If test light does not illuminate, check for open in Red/Brown wire between high speed radiator fan relay and fuse "B" (30-amp) in PDC. Repair wiring as necessary. Also check fuse "B". Replace fuse as necessary.
- Measure resistance of Yellow wire between terminal No. 4 at radiator fan motor harness connector and terminal "D" at high speed radiator fan relay socket in PDC. See Figure and Fig 1 . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Yellow wire.
- At this time, high speed radiator fan relay is assumed to be defective. Replace high speed radiator fan relay.