For 1990-2009 cars

## Blower Motor Medium Speed Inoperative Buick

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 |

1. Turn the ignition switch to the RUN position.
2. Set the HVAC control to RECIRC.
3. Set the blower speed to M1.
4. Use a test lamp to backprobe the blower resistor assembly connector between terminal C and ground.

Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp light?

--

Go to Step 2

Go to Step 7

2 |

1. Switch the blower speed to M2.
2. Use a test lamp to backprobe the blower resistor assembly connector from terminal B to ground. Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp light?

--

Go to Step 3

Go to Step 4

3 | Inspect the blower resistor assembly for a poor connection. Refer to Intermittents and Poor Connections . If the connection is OK, replace the blower resistor asembly. Refer to Blower Motor Resistor Replacement . Is the repair complete? | -- | System OK | --
4 | Inspect for an open in CKT 72. Did you find an open? | -- | Go to Step 5 | Go to Step 6
5 | Repair the open in CKT 72. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 6 | --
6 |

1. Inspect the following components for a poor connection:

• | Connector C200 terminal G2. Refer to Intermittents and Poor Connections .

• | The HVAC control assembly connector C1 terminal D. Refer to Intermittents and Poor Connections .

2. If the connections are OK, replace the HVAC control assembly. Refer to Control Assembly Replacement .

Is the repair complete?

--

System OK

--

7 | Inspect for an open in CKT 63. Did you find an open? | -- | Go to Step 8 | Go to Step 9
8 | Repair the open in CKT 63. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 9 | --
9 |

1. Inspect the following components for a poor connection:

• | Connector C200 terminal E12. Refer to Intermittents and Poor Connections .

• | The HVAC control assembly connector C1 terminal B. Refer to Intermittents and Poor Connections .

2. If the connections are OK, replace the HVAC control assembly. Refer to Control Assembly Replacement .

Is the repair complete?

--

System OK

--

## Blower Motor Medium Speed Inoperative Oldsmobile

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 |

1. Turn the ignition switch to the RUN position.
2. Set the HVAC control to MAX-A/C.
3. Set the blower speed to M1.
4. Use a test lamp to backprobe the blower resistor assembly connector between terminal C and ground.

Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp light?

--

Go to Step 2

Go to Step 7

2 |

1. Switch the blower speed to M2.
2. Use a test lamp to backprobe the blower resistor assembly connector from terminal B to ground. Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp light?

--

Go to Step 3

Go to Step 4

3 |

1. Inspect the blower resistor assembly for a poor connection. Refer to Intermittents and Poor Connections .
2. If the connection is OK, replace the blower resistor asembly. Refer to Blower Motor Resistor Replacement .

Is the repair complete?

--

System OK

--

4 | Inspect for an open in CKT 72. Did you find an open? | -- | Go to Step 5 | Go to Step 6
5 | Repair the open in CKT 72. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 6 | --
6 |

1. Inspect the following components for a poor connection:

• | Connector C200 terminal G2. Refer to Intermittents and Poor Connections .

• | The HVAC control assembly connector C3 terminal D. Refer to Intermittents and Poor Connections .

2. If the connections are OK, replace the HVAC control assembly. Refer to Control Assembly Replacement .

Is the repair complete?

--

System OK

--

7 | Inspect for an open in CKT 63. Did you find an open? | -- | Go to Step 8 | Go to Step 9
8 | Repair the open in CKT 63. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 9 | --
9 |

1. Inspect the following components for a poor connection:

• | Connector C200 terminal E12. Refer to Intermittents and Poor Connections .

• | The HVAC control assembly connector C3 terminal C. Refer to Intermittents and Poor Connections .

2. If the connections are OK, replace the HVAC control assembly. Refer to Control Assembly Replacement .

Is the repair complete?

--

System OK

--

## Blower Motor Medium Speed Inoperative Pontiac

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 |

1. Turn the ignition switch to the RUN position.
2. Set the HVAC control to MAX-A/C.
3. Set the blower speed to M1.
4. Use a test lamp to backprobe the blower resistor assembly connector between terminal C and ground.

Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp light?

--

Go to Step 2

Go to Step 7

2 |

1. Switch the blower speed to M2.
2. Use a test lamp in order to backprobe the blower resistor assembly connector from terminal B to ground.

Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp light?

--

Go to Step 3

Go to Step 4

3 |

1. Inspect the blower resistor assembly for a poor connection. Refer to Intermittents and Poor Connections .
2. If the connection is OK, replace the blower resistor assembly.

Refer to Blower Motor Resistor Replacement .

Is the repair complete?

--

System OK

--

4 | Inspect for an open in CKT 72. Did you find an open? | -- | Go to Step 5 | Go to Step 6
5 | Repair the open in CKT 72. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 6 | --
6 |

1. Inspect the following components for a poor connection:

• | Connector C200 terminal G2. Refer to Intermittents and Poor Connections .

• | The heater-A/C control assembly connector C1 terminal B. Refer to Intermittents and Poor Connections .

2. If the connections are OK, replace the HVAC control assembly. Refer to Control Assembly Replacement .

Is the repair complete?

--

System OK

--

7 | Inspect for an open in CKT 63. Did you find an open? | -- | Go to Step 8 | Go to Step 9
8 | Repair the open in CKT 63. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 9 | --
9 |

1. Inspect the following components for a poor connection:

• | Connector C200 terminal E12. Refer to Intermittents and Poor Connections .

• | The HVAC control assembly connector C1 terminal A. Refer to Intermittents and Poor Connections .

2. If the connections are OK, replace the HVAC control assembly. Refer to Control Assembly Replacement .

Is the repair complete?

--

System OK

--