Blower Motor Inoperative
*BLOWER MOTOR INOPERATIVE
For a complete wiring diagram Consult Diagrams/Electrical
Diagnostic Test
1. FUSE CHECK
Turn the ignition off.
Remove and inspect Power Distribution Center Fuse #1.
Is the fuse open?
Yes
- Go To2
No
- Go To5
2. POWER DISTRIBUTION CENTER FUSE #1
Turn the ignition off.
Replace the Power Distribution Center Fuse #1.
Turn the ignition on.
Turn the blower on and operate it in all speeds and modes.
Does the blower motor operate properly without blowing the fuse?
Yes
- Check the Blower Motor Relay Output circuit for an intermittent short to ground. Repair as necessary.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
No
- Go To3
3. BLOWER MOTOR RELAY SHORTED TO GROUND
Turn the ignition off.
Remove Blower Motor Relay from the Power Distribution Center.
Measure the resistance between the Blower Motor Relay terminal 29 and terminal 28.
Measure the resistance between the Blower Motor Relay terminal 29 and terminal 26.
Is the resistance below 10K ohms?
Yes
- Replace the Blower Motor Relay and fuse.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
No
- Go To4
4. BLOWER MOTOR RELAY OUTPUT CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the Blower Motor harness connector.
Measure the resistance between ground and the Blower Motor Relay Output circuit.
Is the resistance below 10K ohms?
Yes
- Repair the Blower Motor Relay Output circuit for a short to ground and replace the fuse.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
No
- Replace the Blower Motor and fuse.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
5. CHECK FOR POWER TO THE BLOWER MOTOR HIGH DRIVER CIRCUIT
Turn the ignition off.
Ensure Power Distribution Center Fuse #1 is installed.
Turn the ignition on.
NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
Using a 12-volt test light connect to ground, back probe the Blower Motor High Driver circuit in the Blower Motor harness connector.
Does the test light illuminate brightly?
Yes
- Go To6
No
- Go To8
6. BLOWER MOTOR HIGH DRIVER CIRCUIT OPEN
Turn the ignition off.
Disconnect the A/C - Heater Control Module C1 harness connector.
Turn the ignition on.
NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
Using a 12-volt test light connected to ground, back probe the Blower Motor High Driver circuit in the A/C - Heater Control Module C1 harness connector.
Does the test light illuminate brightly?
Yes
- Go To7
No
- Repair the Blower Motor High Driver circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
7. GROUND CIRCUIT OPEN
Turn the ignition off.
Disconnect the A/C - Heater Control Module C1 harness connector.
Measure the resistance between ground and the Ground circuit.
Is the resistance below 5.0 ohms?
Yes
- Replace the A/C - Heater Control Module.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
No
- Repair the Ground circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
8. CHECKING BLOWER MOTOR RELAY AND RELAY CIRCUITS
Perform the Blower Motor Relay, Relay Test and Relay Circuit Test.
Do the relay and circuits test Ok?
Yes
- Go To9
No
- Repair as necessary.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
9. BLOWER MOTOR HIGH DRIVER CIRCUIT OPEN
Turn the ignition off.
Disconnect the Blower Motor harness connector.
Disconnect the A/C - Heater Control Module C1 harness connector.
Measure the resistance of the Blower Motor High Driver circuit between the Blower Motor harness connector and the A/C - Heater Control Module C1 harness connector.
Is the resistance below 5 ohms?
Yes
- Replace the Blower Motor.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
No
- Repair the Blower Motor High Driver circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.