The number below refers to the step number in the diagnostic table.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: The blower motor is ON while the blower motor switch is in the OFF position. | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Important: The blower motor switch must remain in the OFF position during this diagnostic procedure.
Is the blower motor OFF? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
3 |
Does the blower motor continue to operate? | Go to Step 11 | Go to Step 4 |
4 | Probe the high blower motor control circuit of the blower motor relay 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 high blower motor control circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 10 |
Probe the blower motor supply voltage circuit, from the blower motor resistor with a test lamp that is connected to a good ground. Does the test lamp illuminate? | Go to Step 7 | Go to Step 9 | |
7 | Test the blower motor supply voltage circuit between the blower motor relay and the blower motor resistor for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 8 |
8 | Test the low, medium 1, and medium 2, blower motor control circuits for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 10 |
9 | 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 . Did you find and correct the condition? | Go to Step 14 | Go to Step 12 |
10 | Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 13 |
11 | Repair the short to voltage on the blower motor supply voltage circuit between the blower motor and blower motor relay. Refer to Wiring Repairs . Did you complete the repair? | Go to Step 14 | -- |
12 | Replace the blower motor relay. Refer to Relay Replacement. Did you complete the replacement? | Go to Step 14 | -- |
13 | Replace the HVAC control module. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 14 | -- |
14 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |