Blower Motor Speeds Incorrect
BLOWER MOTOR SPEEDS INCORRECT
For a complete wiring diagram refer to the Wiring Information Electrical Diagrams
1. CHECK BLOWER MOTOR OPERATION
1. Turn the Blower control to the Off position.
2. Turn the ignition on.
Does the blower run?
Yes
- Go To 2
No
- Go To 3
2. BLOWER MOTOR DRIVER CIRCUIT(S) SHORTED TO GROUND
1. Turn the ignition off.
2. Disconnect the A/C - Heater Control Module C1 harness connector.
3. Disconnect the Blower Motor Resistor Block harness connector.
4. Measure the resistance between ground and each of the Blower Motor Driver circuits.
Is the resistance below 10K ohms on any of the circuits?
Yes
- Repair all Blower Motor Driver circuits with a resistance below 10K ohms for a short to ground.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
No
- Replace the A/C - Heater Control Module.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
3. CHECK FOR POWER TO THE BLOWER MOTOR DRIVER CIRCUITS
1. Turn the ignition off.
2. Disconnect the A/C - Heater Control Module C1 harness connector.
3. Turn the ignition on.
NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
4. Using a 12-volt test light connected to ground, back probe each of the Blower Motor Driver circuits (cavities 2, 3, 7, and 10) in the A/C - Heater Control Module C1 harness connector.
Does the test light illuminate brightly on each circuit?
Yes
- Go To 4
No
- Go To 6
4. BLOWER MOTOR DRIVER CIRCUIT(S) SHORTED TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the A/C - Heater Control Module C1 harness connector.
3. Disconnect the Blower Motor Resistor Block harness connector.
4. Measure the voltage of each of the Blower Motor Driver circuits (cavities 2, 3, 7, and 10).
Is there any voltage present?
Yes
- Repair all Blower Motor Driver circuits with voltage present for a short to voltage.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
No
- Go To 5
5. BLOWER MOTOR DRIVER CIRCUITS SHORTED TOGETHER
1. Turn the ignition off.
2. Disconnect the A/C - Heater Control Module C1 harness connector.
3. Disconnect the Blower Motor Resistor Block harness connector.
4. Measure the resistance between the Low Blower Motor Driver circuit and the M1, M2, and Blower Motor High Driver circuit.
5. Measure the resistance between the M1 Blower Motor Driver circuit and the M2 and Blower Motor High Driver circuit.
6. Measure the resistance between the M2 Blower Motor Driver circuit and the Blower Motor High Driver circuit.
Is the resistance below 10K ohms between any of the circuits?
Yes
- Repair the Blower Motor Driver circuits with a resistance below 10K ohms for a short to each other.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
No
- Replace the A/C - Heater Control Module.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
6. BLOWER MOTOR DRIVER CIRCUIT(S) OPEN
1. Turn the ignition off.
2. Disconnect the A/C - Heater Control Module C1 harness connector.
3. Disconnect the Blower Motor Resistor Block harness connector.
4. Measure the resistance of each Blower Motor Driver circuit between the Blower Motor Resistor Block harness connector and the A/C - Heater Control Module C1 harness connector.
Is the resistance below 5.0 ohms on each of the circuits?
Yes
- Replace the Blower Motor Resistor Block.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.
No
- Repair all Blower Motor Driver circuits with a resistance above 5 ohms for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.