Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: HVAC Schematics DEFINITION: The auxiliary blower motor is ON while the auxiliary mode switch is in the OFF position. | |||
1 | Did you perform the HVAC Diagnostic System Check? | Go to Step 2 | |
2 |
Is the auxiliary blower motor OFF? | Go to Step 3 | Go to Step 4 |
3 |
Is the auxiliary blower motor OFF? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 14 |
4 | Place the rear auxiliary blower motor switch in the OFF position Does the auxiliary blower motor continue to operate? | Go to Step 5 | Go to Step 11 |
5 |
Important: The front auxiliary blower motor switch must remain in the OFF position during all further diagnostic steps.
Does the auxiliary blower motor continue to operate? | Go to Step 6 | Go to Step 10 |
6 | Test the auxiliary blower motor control circuit between the auxiliary blower motor resistor assembly and the auxiliary blower motor relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 18 | Go to Step 7 |
7 | Test the auxiliary blower motor control circuit between the auxiliary blower motor and the auxiliary blower motor relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 18 | Go to Step 8 |
8 |
Does the test lamp illuminate? | Go to Step 9 | Go to Step 12 |
9 | Test the high blower motor control circuit of the auxiliary blower motor relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 18 | Go to Step 13 |
10 | Test the auxiliary blower motor low speed control circuit and the auxiliary blower motor medium speed control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 18 | Go to Step 13 |
11 | Test the auxiliary blower motor control circuit and the auxiliary blower motor medium speed control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 18 | Go to Step 13 |
12 | Inspect for poor connections at the harness connector of the auxiliary 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 18 | Go to Step 15 |
13 | Inspect for poor connections at the harness connector of the front auxiliary blower motor switch. 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 18 | Go to Step 16 |
14 | Inspect for poor connections at the harness connector of the auxiliary 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 18 | Go to Step 17 |
15 | Replace the auxiliary blower motor relay. Did you complete the replacement? | Go to Step 18 | -- |
16 | Replace the front auxiliary blower motor switch. Refer to Auxiliary Blower Motor Switch Replacement . Did you complete the replacement? | Go to Step 18 | -- |
17 | Replace the auxiliary HVAC control assembly. Refer to Auxiliary Heater and Air Conditioning Control Module Replacement . Did you complete the replacement? | Go to Step 18 | -- |
18 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
