Did you perform the HVAC Systems Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check

Inspect the HEATER BLOWER fuse.

Is the fuse open?

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Go to Step 3

Go to Step 4

Test the battery feed circuit to the blower control module (CKT A465) for a short to ground. Refer to Testing for Short to Ground in Wiring Systems.

Did you find a short to ground in the battery feed circuit?

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Go to Step 5

Go to Step 6

Remove the HEATER BLOWER fuse and test for voltage at the fuse block terminal (one terminal is hot at all times).

Is the voltage within the specified value?

11 - 13 V

Go to Step 7

Go to Step 8

1. Repair the short to ground. Refer to Wiring Repairs in Wiring Systems.
2. Replace the HEATER BLOWER fuse.

Is the repair complete?

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Go to Step 18

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The short to ground may be intermittent at this time. Refer to Inducing Intermittent Fault Conditions in Wiring Systems. Replace the HEATER BLOWER fuse.

Did you replace the fuse?

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Go to Step 18

Go to Step 13

1. Reinstall the HEATER BLOWER fuse.
2. Disconnect the blower control module main electrical connector.
3. Connect the negative lead of the DMM to terminal 3 of the blower control module.
4. With the positive lead measure the voltage at terminal 1 of the blower control module.

Is the voltage within the specified value?

11 - 13 V

Go to Step 9

Go to Step 10

Locate and repair an open to the HEATER BLOWER fuse battery feed circuit (CKT A60). Refer to Testing for Continuity in Wiring Systems.

Is the repair complete?

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Go to Step 18

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Reconnect the blower control module main electrical connector and measure the voltage at terminal 6 (motor+).

Is the voltage within the specified value?

11 - 13 V

Go to Step 11

Go to Step 14

1. Move the negative lead of the DMM to another ground location.
2. Re-measure the voltage at terminal 1.

Is the voltage within the specified value?

11 - 13 V

Go to Step 15

Go to Step 16

1. Disconnect the blower motor ground (BRN wire) from the blower control module.
2. Connect a fused jumper wire between the BRN wire and ground.
3. Turn the ignition switch to the ON position.

Does the blower motor operate?

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Go to Step 14

Go to Step 17

Test for an open or a short to ground in CRK FP812. Refer to Circuit Testing in Wiring Systems.

Did you find the condition?

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Go to Step 13

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Repair the open or short to ground in CRK FP812. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to Step 18

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Replace the blower control module.

Is the replacement complete?

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Go to Step 18

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Locate and repair the open in CKT F812 (BLK).

Is the repair complete?

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Go to Step 18

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Locate and repair the open in CKT A465 (RED).

Is the repair complete?

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Go to Step 18

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

Is the replacement complete?

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Go to Step 18

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Operate the system for which the symptom occurred.

Is the symptom still present?

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System OK