Low Speed Resistance

2.8 ohms

Medium 1 Speed Resistance

1.5 ohms

Medium 2 Speed Resistance

0.6 ohms

High Speed Resistance

0 ohms

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: The blower motor operates in at least one, but not all, speed positions.

Did you perform the HVAC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Manual

1. Turn ON the ignition, with the engine OFF.
2. Place the blower motor switch in each speed position.

Does the blower motor operate at the desired speeds?

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

Go to Step 3

Does the blower motor operate at high speed?

Go to Step 4

Go to Step 6

Test the applicable blower motor speed control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 5

1. Disconnect the blower motor resistor assembly.
2. Test the applicable blower motor resistor circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did the blower motor resistor test OK?

Go to Step 12

Go to Step 11

1. Disconnect the blower relay.
2. Connect a 30-amp fused jumper between the blower motor high speed control circuit and the blower motor high speed ground circuit.

Does the blower motor operate?

Go to Step 9

Go to Step 7

Test the blower relay switch feed circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 8

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

Did you find and correct the condition?

Go to Step 17

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

Did you find and correct the condition?

Go to Step 17

Go to Step 10

Test the blower relay coil control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 13

Inspect for poor connections at the harness connector of the blower motor resistor 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 17

Go to Step 14

Inspect for poor connections at the harness connector of the 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 17

Go to Step 15

Inspect for poor connections at the harness connector of the blower 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 17

Go to Step 16

Replace the blower motor resistor. Refer to Blower Motor Resistor Assembly Replacement in Heating, Ventilation and Air Conditioning.

Did you complete the replacement?

Go to Step 17

--

Replace the blower motor switch. Refer to Heater and Air Conditioning Control Replacement .

Did you complete the replacement?

Go to Step 17

--

Replace the blower relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 17

--

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2