GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Heater Blower Controls System Check?

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Go to Step 2

Go to Heater Blower Controls System Check

2

  1. Place the ignition switch in the RUN position.
  2. Place the rear heat switch in the HIGH position.
  3. Use a test lamp J 35616-200 in order to backprobe from the rear heater switch CKT 1924 (WHT) cavity A to ground.

Did the test lamp light?

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Go to Step 3

Go to Step 4

3

Repair the open in CKT 1924 (WHT) between the rear heater switch and the rear heater resistor pack.

Is the repair complete?

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Go to Heater Blower Controls System Check

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4

Inspect for a poor connection at the rear heater switch.

Did you find a poor connection?

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Go to Step 6

Go to Step 5

5

Replace the rear heater switch.

Refer to Control Switch Replacement - Auxiliary in Heating and Ventilation (Non-A/C).

Is the repair complete?

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Go to Heater Blower Controls System Check

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6

Repair the poor connection.

Is the repair complete?

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Go to Heater Blower Controls System Check

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