GM Service Manual Online
For 1990-2009 cars only

Blower Motor Inoperative in One Speed Only High Speed Operates Normally

Step

Action

Value(s)

Yes

No

1

Did you complete the Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check

2

  1. Disconnect the blower resistor connector.
  2. Place the ignition switch in the RUN position.
  3. Place the blower switch in the inoperative position.
  4. Connect a test lamp from the blower resistor connector inoperative terminal (position 1 (low) =B, 2 (M1) =A, 3 (M2) =D) to ground on the harness connector.

Does the test lamp illuminate?

--

Go to Step 3

Go to Step 5

3

Test for and repair a poor connection at the blower resistor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and repair a poor connection?

--

Go to Step 9

Go to Step 4

4

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

Did you complete the replacement?

--

Go to Step 9

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5

Probe with a test lamp between the HVAC control (blower switch) connector C1 of the inoperative terminal (position 1 (low) =A, 2 (M1) =C, 3 (M2) =D) and ground.

Does the test lamp illuminate?

--

Go to Step 6

Go to Step 7

6

Repair a poor connection or an open in the inoperative circuit (position 1 (low) =60, 2 (M1) =63, 3 (M2) =72). Refer to Connector Repairs or Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 9

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7

Test for and repair a poor connection at the HVAC control (blower switch). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and repair a poor connection?

--

Go to Step 9

Go to Step 8

8

Replace the HVAC control blower switch. Refer to HVAC Control Blower Switch Replacement .

Did you complete the replacement?

--

Go to Step 9

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9

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3