GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Has the Heater Blower Controls System Check been performed?

--

Go to Step 2

Go to Heater Blower Controls System Check

2

  1. Place the ignition switch in the RUN position.
  2. Place the blower switch in the Med2 position (next to the HI position).
  3. Disconnect the connector at the blower resistor.
  4. Connect a DMM (volts) between the blower resistor connector, cavity D, and ground.

Is battery voltage present?

--

Go to Step 4

Go to Step 3

3

  1. Disconnect connector C2 at the HVAC control module.
  2. Connect a DMM (continuity) between pins G and A of the HVAC control module connector C2.
  3. Turn the blower switch to the Med2 position (next to the HI position).

Is continuity present?

--

Go to Step 6

Go to Step 5

4

Replace the blower resistor. Refer to Blower Motor Relay Replacement .

Is the repair complete?

--

Go to Heater Blower Controls System Check

--

5

Replace the HVAC control module. Refer to Control Assembly Replacement .

Is the repair complete?

--

Go to Heater Blower Controls System Check

--

6

Locate and repair the open in CKT 72 (LT BLU) between the HVAC control module and the blower resistor.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Heater Blower Controls System Check

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