Blower Motor: Testing and Inspection
Note: For Front Blower Motor component testing Manufacturer Code Charts
Note: For diagnostic trouble code descriptions Diagnostic Trouble Code Descriptions
Rear Blower Motor Circuit Troubleshooting
1. Check the No. 55 (30 A) fuse in the under-hood fuse/relay box, and the No. 3 (7.5 A) fuse in the driver's under-dash fuse/relay box.
Are the fuses OK?
YES - Go to step 2.
NO - Replace the fuse(s), and recheck.
2. Turn the ignition switch ON (II).
3. Connect the No. 2 terminal of the rear blower motor 2P connector to body ground with a jumper wire.
Does the rear blower motor run?
YES - Go to step 4.
NO - Go to step 16.
4. Disconnect the jumper wire.
5. Disconnect the rear blower resistor 5P connector.
6. Connect the No. 3 terminal of the rear blower resistor 5P connector to body ground with a jumper wire.
Does the blower motor run?
YES - Go to step 7.
NO - Repair open in the wire between the rear blower motor and the rear blower resistor.
7. Disconnect the jumper wire.
8. Turn the ignition switch OFF.
9. Measure the resistance between the No. 3 and No. 5 terminals of the rear blower resistor.
Is there about 4 - 5 Ohms?
YES - Go to step 10.
NO - Replace the rear blower resistor.
10. Disconnect rear heater-A/C control switch connector A (7P).
11. Reconnect the blower resistor 5P connector.
12. Ground each of the rear heater-A/C control switch connector A (7P) terminals individually in the following order: No. 7, 3, 4, 6 and 1.
Does the blower motor run at progressively higher speeds?
YES - Go to step 13.
NO - Repair any open or cause of excessive resistance in the appropriate wire(s) between the blower resistor and the rear heater-A/C control switch.
13. Disconnect rear heater-A/C control switch connector B (10P).
14. Check for continuity between the No. 5 terminal of rear heater-A/C control switch connector A (7P) and body ground.
Is there continuity?
YES - Go to step 15.
NO - Check for an open in the wire between the rear heater-A/C control switch and body ground. If the wire is OK, check for poor ground at G501.
15. Check for continuity between the No. 7 terminal of rear heater-A/C control switch connector B (10P) and body ground.
Is there continuity?
YES - Test the rear heater-A/C control switch.
NO - Check for an open in the wire between the rear heater-A/C control switch and body ground. If the wire is OK, check for poor ground at G501.
16. Disconnect the jumper wire.
17. Disconnect the rear blower motor 2P connector.
18. Measure the voltage between the No. 1 terminal of the rear blower motor 2P connector and body ground.
Is there battery voltage?
YES - Replace the rear blower motor.
NO - Go to step 19.
19. Turn the ignition switch OFF.
20. Remove the rear blower motor relay from the left side of rear heater-A/C unit, and test it.
Is the relay OK?
YES - Go to step 21.
NO - Replace the rear blower motor relay.
21. Measure the voltage between the No. 1 terminal of the rear blower motor relay 4P connector and body ground.
Is there battery voltage?
YES - Go to step 22.
NO - Repair open in the wire between the No. 55 fuse in the under-hood fuse/relay box and the rear blower motor relay.
22. Turn the ignition switch ON (II).
23. Measure the voltage between the No. 2 terminal of the rear blower motor relay 4P connector and body ground.
Is there battery voltage?
YES - Go to step 24.
NO - Repair open in the wire between the No. 3 fuse in the driver's under-dash fuse/relay box and the rear blower motor relay.
24. Turn the ignition switch OFF.
25. Check for continuity between the No. 4 terminal of the rear blower motor relay 4P connector and body ground.
Is there continuity?
YES - Repair open in the wire between the rear blower motor relay and the rear blower motor.
NO - Check for an open in the wire between the rear blower motor relay and body ground. If the wire is OK, check for poor ground at G501.