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 an unpowered test lamp in order to backprobe the blower relay connector between terminal 87A 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 an unpowered test lamp in order to backprobe the blower relay connector between terminal 87A and 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 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 an unpowered test lamp in order to backprobe the blower relay connector between terminal 87A 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 an unpowered test lamp in order to backprobe the blower relay connector from terminal 87A 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 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 an unpowered test lamp in order to backprobe the blower relay connector between terminal 87A 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 an unpowered test lamp in order to backprobe the blower relay connector from terminal 87A 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

--