Schematic Reference: HVAC Schematics

Did you review the Air Delivery Description and Operation and the Air Temperature Description and Operation perform the necessary inspections?

Go to Step 2

Go to Symptoms - HVAC Systems - Manual

Operate the blower motor at each speed.

Does the blower motor operate at any speed?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

1. Disconnect the blower motor connector.
2. Connect a test lamp across the blower motor connector.
3. Start the engine.
4. Turn the blower switch to any position except OFF.

Does the test lamp light?

Go to Step 11

Go to Step 4

Test the blower motor supply voltage circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 5

Test the ground circuit between the blower motor and S200 for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 6

Test that the HTR relay is open between terminals 4 and 5 and that there is continuity between terminals 4 and 2. Refer to Fuse and Relay Block 3 in Wiring Systems.

Did the relay test OK?

Go to Step 7

Go to Step 12

Test the HTR relay coil supply voltage circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 8

Test the HTR relay control circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 9

Test the blower switch ground circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 10

Test the blower switch for a high resistance or an open. Refer to Circuit Testing in Wiring Systems and Blower Switch Replacement .

Did you find and correct the condition?

Go to Step 15

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Inspect for a poor connection at the harness connector of the blower motor. 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 15

Go to Step 13

Inspect for a poor connection at the harness connector of the heater 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 15

Go to Step 14

Replace the blower motor. Refer to Blower Motor and Fan Replacement .

Did you complete the replacement?

Go to Step 15

Replace the heater relay. Refer to Blower Motor Relay Replacement .

Did you complete the replacement?

Go to Step 15

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3