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. Disconnect the auxiliary HVAC control module, front switch.
  2. Connect a J 39200 (continuity) between cavity B of the switch connector and ground.

Is continuity present?

--

Go to Step 4

Go to Step 3

3

Locate and repair the open in CKT 150 (BLK) between the auxiliary HVAC control module, front switch and ground G200. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Heater Blower Controls System Check

--

4

Connect a J 39200 (continuity) between pin B and pin E, F and D while rotating the blower switch through Low, Med, and High.

Is continuity present in all modes?

--

Go to Step 6

Go to Step 5

5

Replace the auxiliary HVAC control module, front switch. Refer to Control Switch Replacement - Auxiliary .

Is the repair complete?

--

Go to Heater Blower Controls System Check

--

6

  1. Disconnect the auxiliary blower resistor connector.
  2. Disconnect the auxiliary blower motor connector.
  3. Connect a J 39200 (continuity) between cavity B of the resistor connector and cavity A of the blower motor connector.

Is continuity present?

--

Go to Step 8

Go to Step 7

7

Locate and repair the open in CKT 1172 (YEL) between splice S402 and the blower motor. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Heater Blower Controls System Check

--

8

Connect a J 39200 (continuity) between cavity B of the blower motor connector and ground.

Is continuity present?

--

Go to Step 9

Go to Step 10

9

Replace the auxiliary blower motor. Refer to Auxiliary Blower Motor Replacement .

Is the repair complete?

--

Go to Heater Blower Controls System Check

--

10

Locate and repair the open in CKT 150 (BLK) between the blower motor and ground G400. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Heater Blower Controls System Check

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