Important: A short to ground will cause an open fuse. Before performing this diagnostic procedure, inspect the fuses for an open.

Did you perform the HVAC Blower Controls System Check?

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Go to Step 2

Go to HVAC Blower Controls System Check

1. Turn the ignition switch to the ON position.
2. Use the J 39200 Digital Multimeter (DMM) in order to measure the voltage between terminal C of the heater A/C control assembly connector C2 and ground.

Does the voltage measured equal the specified value?

B+

Go to Step 3

Go to Step 4

1. Disconnect the heater A/C control assembly connector C2.
2. Use the J 39200 DMM in order to measure the voltage between terminal C and terminal K of the heater A/C control assembly connector C2.

Does the voltage measured equal the specified value?

B+

Go to Step 5

Go to Step 6

Use the J 39200 DMM in order to measure the voltage between terminal A11 of the underhood wiring harness junction block connector C3 and ground.

Does the voltage measured equal the specified value?

B+

Go to Step 7

Go to Step 8

1. Reconnect the heater A/C control assembly connector C2.
2. Use the J 39200 DMM in order to backprobe the heater A/C control assembly connector C2.
3. Measure the voltage between terminal G and ground.
4. Turn the temperature control from COLD to HOT.

Does the voltage vary within the specified range?

1-12 V

Go to Step 9

Go to Step 10

Repair the open in CKT 251 between the heater A/C control assembly and ground splice pack G204. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to HVAC Blower Controls System Check

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Repair the open in CKT 41 between the underhood wiring harness junction block and the heater A/C control assembly. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to HVAC Blower Controls System Check

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Replace the underhood wiring harness junction block. Refer to Relay/Fuse Center Replacement in Wiring Systems.

Is the repair complete?

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Go to HVAC Blower Controls System Check

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1. Disconnect the air temperature actuator connector.
2. Connect the J 39200 DMM between terminal 8 of the air temperature actuator connector and ground.
3. Turn the temperature control from COLD to HOT.

Does the voltage vary within the specified range?

1-12 V

Go to Step 11

Go to Step 12

Replace the heater A/C control assembly.

Is the repair complete?

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Go to HVAC Blower Controls System Check

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Connect the J 39200 DMM between terminal 10 of the air temperature actuator connector and ground.

Does the voltage measured equal the specified value?

B+

Go to Step 13

Go to Step 14

Repair the open in CKT 733 between the air temperature actuator and the heater A/C control assembly. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to HVAC Blower Controls System Check

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Use the J 39200 DMM in order to measure the voltage between terminal 7 and terminal 10 of the air temperature actuator connector.

Does the voltage measured equal the specified value?

B+

Go to Step 15

Go to Step 16

Repair the open in CKT 41 between the underhood wiring harness junction block and the air temperature actuator. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to HVAC Blower Controls System Check

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Replace the air temperature actuator.

Is the repair complete?

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Go to HVAC Blower Controls System Check

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Repair the open in CKT 251 between the air temperature actuator and ground splice pack G204. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to HVAC Blower Controls System Check

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