GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2000 🢒 Montana 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Blower Motor Inoperative in One Speed Only

Blower Motor Inoperative in One Speed Only Front, High Speed Operates Normally

Step

Action

Value(s)

Yes

No

1

Was the entire HVAC diagnostic system check performed?

--

Go to Step 2

Go to Diagnostic System Check

2
  1. Disconnect the blower motor resistor connector.
  2. Place the ignition switch in the RUN position.
  3. Place the heater-A/C control in the inoperative position.
  4. Connect a test lamp from the blower motor resistor connector inoperative terminal (1=B, 2=A, 3=D, 4=C) to ground on the harness connector. Refer to Circuit Testing in Wiring Systems.

Is the test lamp on?

--

Go to Step 3

Go to Step 4

3

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

Is the repair complete?

--

Go to Step 7

--

4

Probe with a test lamp between the heater-A/C control connector C1 of the inoperative terminal (1=H, 2=G, 3=F, 4=E) and ground. Refer to Circuit Testing in Wiring Systems.

Is the test light on?

--

Go to Step 5

Go to Step 6

5

Repair the poor connection or an open in the inoperative circuit (1=60, 2=63, 3=72, 4=73). Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 7

--

6

Replace the heater-A/C control. Refer to HVAC Module Assembly Replacement .

Is the repair complete?

--

Go to Step 7

--

7
  1. Turn the ignition switch to the OFF position.
  2. Reconnect all connectors/components disconnected.

Have all repairs been made?

--

Go to Diagnostic System Check

--

Blower Motor Inoperative in One Speed Only Rear, High Speed Operates Normally

Step

Action

Value(s)

Yes

No

1

Was the entire HVAC diagnostic system check performed?

--

Go to Step 2

Go to Diagnostic System Check

2

Is one speed inoperative from the auxilliary heater-A/C control (auxilliary blower switch) only?

--

Go to Step 3

Go to Step 4

3
  1. Place the ignition switch in the RUN position.
  2. Turn the rear window wiper/washer and multi-function switch to the rear position.
  3. Place the auxilliary heater-A/C control (auxilliary blower switch) in the inoperative position.
  4. Connect a test lamp from the auxiliary heater-A/C control connector C2 inoperative terminal (1=D, 2=E, 3=F) to B+. Refer to Circuit Testing in Wiring Systems.

Is the test lamp on?

--

Go to Step 5

Go to Step 6

4

Is one speed inoperative from the rear window wiper/washer and multi-fuction switch (auxilliary blower switch) only?

--

Go to Step 7

Go to Step 8

5

Repair the poor connection or open in the inoperative circuit (1=1176, 2=1072, 3=1052). Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 11

--

6

Replace the auxiliary heater-A/C control. Refer to Auxiliary HVAC Module Replacement .

Is the repair complete?

--

Go to Step 11

--

7

Probe with a test lamp between the rear window wiper/washer and multi-function switch connector C2 of the inoperative terminal (1=A, 2=C, 3=B) and B+. Refer to Circuit Testing in Wiring Systems.

Is the test lamp on?

--

Go to Step 5

Go to Step 9

8
  1. One speed is inoperative from both switches.
  2. Disconnect the auxiliary blower motor resistor connector.
  3. Place the auxiliary blower switch in the inoperative position.
  4. Connect a test lamp from the auxiliary blower motor resistor connector inoperative terminal (1=C, 2=D, 3=B) to B+. Refer to Circuit Testing in Wiring Systems.

Is the test lamp on?

--

Go to Step 10

Go to Step 5

9

Replace the rear window wiper/washer and multi-function switch. Refer to Auxiliary Air Conditioning (A/C) Control Assembly Replacement - Front .

Is the repair complete?

--

Go to Step 11

--

10

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

Is the repair complete?

--

Go to Step 11

--

11
  1. Turn the ignition switch to the OFF position.
  2. Reconnect all connectors/components disconnected.

Have all repairs been made?

--

Go to Diagnostic System Check

--