1. Place the heater A/C mode control in the VENT position.
2. Place the blower control in the HI position.
3. Use a test lamp connected to B+ to check for a short to ground on circuit 706 (LT BLU) at the heater-A/C harness connector terminal 4.

Does the test lamp light?

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Go to Step 3

Go to Step 2

1. Reconnect the heater-A/C control harness connector.
2. Use a test lamp connected to B+ to check for a short to ground on circuit 706 (LT BLU) between the vacuum/electric harness connector terminal 4 and the heater A/C control connector C 2, terminal A 7.

Does the test lamp light?

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Go to Step 4

Go to Step 5

Locate and repair a short to ground on circuit  706 (LT BLU) .

Is the repair complete?

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System OK

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Replace the vacuum/electric solenoid module. Refer to Vacuum Electrical Solenoid Replacement .

Is the repair complete?

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System OK

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Replace the heater-A/C control. For manual systems refer to Control Assembly Replacement and for automatic systems refer to Control Assembly Replacement in Instrumant Panel, Gauges and Console.

Is the repair complete?

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System OK

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