The number(s) below refer to the step number(s) on the diagnostic table.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: HVAC Schematics DEFINITION: The blower motor is ON while the blower motor switch is in the OFF position. | |||
1 | Did you perform the HVAC Diagnostic System Check? | Go to Step 2 | |
2 |
Is the blower motor OFF? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
3 |
Is the blower motor OFF? | Go to Step 4 | Go to Step 8 |
Important: The mode switch must remain in the OFF position during this step. Probe the blower motor relay supply voltage circuit with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 5 | Go to Step 6 | |
5 | Test the blower motor relay supply voltage circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 7 |
6 | Inspect for poor connections at the harness connector of the blower motor relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 9 |
7 | Inspect for poor connections at the harness connector of the HVAC control assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 10 |
8 | Repair the short to voltage in the blower motor supply voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 11 | -- |
9 | Replace the blower motor relay. Refer to Blower Motor Relay Replacement in Heating, Ventilation, and Air Conditioning. Did you complete the replacement? | Go to Step 11 | -- |
10 | Replace the HVAC control assembly. Refer to Heater and Air Conditioning Control Replacement . Did you complete the replacement? | Go to Step 11 | -- |
11 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |