For 1990-2009 cars

## Blower Motor Inoperative at Any Speed 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 HI.
4. Use a test lamp to backprobe the high speed blower relay connection between terminal 30 and ground.

Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp light?

--

Go to Step 2

Go to Step 7

2 | Inspect for an open in CKT 65. Did you find an open? | -- | Go to Step 3 | Go to Step 4
3 | Repair the open in CKT 65. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --
4 | Inspect for an open in CKT 1550. Did you find an open? | -- | Go to Step 5 | Go to Step 6
5 | Repair the open in CKT 1550. Refer to Wiring Repairs in Wiring systems. Is the repair complete? | -- | System OK | --
6 |

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

Is the repair complete?

--

System OK

--

7 | Use a test lamp to backprobe the high speed blower relay connector from terminal 85 to terminal 86. Refer to Probing Electrical Connectors Does the test lamp light? | -- | Go to Step 9 | Go to Step 10
8 |

1. Inspect the high speed blower relay connector for a poor connection. Refer to Intermittents and Poor Connections
2. If the connection is OK, replace the high speed blower relay.

Is the repair complete?

--

System OK

--

9 | Use a test lamp to backprobe the high speed blower relay connector from terminal 87 to ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp light? | -- | Go to Step 8 | Go to Step 23
10 | Use a test lamp to backprobe the high speed blower relay connector from terminal 85 and ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp light? | -- | Go to Step 11 | Go to Step 12
11 |

1. Inspect the high speed blower relay connector for a poor connection. Refer to Intermittents and Poor Connections
2. If the connection is OK, repair the open in circuit 1550 refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

System OK

--

12 | Use a test lamp to backprobe the high speed blower relay connector from terminal 87 and ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp light? | -- | Go to Step 13 | Go to Step 16
13 | Inspect for an open in CKT 188. Did you find an open ? | -- | Go to Step 14 | Go to Step 15
14 | Repair the open in CKT 188. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --
15 |

1. Inspect the following connectors for a poor connection:

• | The HVAC control assembly connector

• | Connector C200. Refer to Intermittents and Poor Connections

2. If the connection is OK, replace the HVAC control assembly. Refer to Control Assembly Replacement .

Is the repair complete?

--

System OK

--

16 |

1. Remove the blower speed relay.
2. Use a test lamp to B+ to backprobe the blower speed relay connector terminal 86.

Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp light?

--

Go to Step 17

Go to Step 20

17 | Inspect for an open in CKT 41. Did you find an open? | -- | Go to Step 19 | Go to Step 18
18 | Repair the open in CKT 41. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --
19 | Replace the blower speed relay. Is the repair complete? | -- | System OK | --
20 | Inspect for an open in CKT 247. Did you find an open? | -- | Go to Step 21 | Go to Step 22
21 | Repair the open in CKT 247. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 22 | --
22 |

1. Inspect the following components for a poor connection:

• | Connector C200

• | The HVAC control assembly connection 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

--

23 |

1. Inspect the A/C maxi fuse.
2. If OK, repair the open in circuit 442.

Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

System OK

--

## Blower Motor Inoperative at Any Speed Oldsmobile

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

1. Turn the ignition switch to the RUN position.
2. Set the HVAC control to MAX.
3. Set the blower speed to HI.
4. Use a test lamp in to backprobe the blower relay connection between terminal 30 and ground.

Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp light?

--

Go to Step 2

Go to Step 7

2 | Inspect for an open in CKT 65. Did you find an open? | -- | Go to Step 3 | Go to Step 4
3 | Repair the open in CKT 65. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --
4 | Inspect for an open in CKT 1550. Did you find an open? | -- | Go to Step 5 | Go to Step 6
5 | Repair the open in CKT 1550. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --
6 |

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

Is the repair complete?

--

System OK

--

7 | Use a test lamp to backprobe the blower relay connector between terminal 85 and terminal 86. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp light? | -- | Go to Step 8 | Go to Step 9
8 |

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

Is the repair complete?

--

System OK

--

9 | Use a test lamp to backprobe the blower relay connector between terminal 85 and ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp light? | -- | Go to Step 4 | Go to Step 11
10 | Repair the open or short to ground in CKT 52. Refer to Wiring Repairs in Wiring Systems. s the repair complete? | -- | System OK | --
11 | Use a test lamp to backprobe the HVAC control assembly connector C3 between terminal B and ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp light? | -- | Go to Step 10 | Go to Step 12
12 | Inspect for an open in the HVAC control assembly connector CKT 41. Did you find an open? | -- | Go to Step 13 | Go to Step 14
13 | Repair the open in the HVAC control assembly connector CKT 41. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --
14 |

1. Inspect the HVAC control assembly connector for a poor connection. Refer to Intermittents and Poor Connections
2. If the connection is OK, replace the HVAC control assembly connector. Refer to Control Assembly Replacement

Is the repair complete?

--

System OK

--

## Blower Motor Inoperative at Any Speed Pontiac

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

1. Turn the ignition switch to the RUN position.
2. Set the Heater-A/C control to MAX.
3. Set the blower speed to HI.
4. Use a test lamp to backprobe the blower relay connection between terminal 30 and ground.

Refer to Probing Electrical Connectors in Wiring Systems.

Does the test lamp light?

--

Go to Step 2

Go to Step 7

2 | Inspect for an open in CKT 65. Did you find an open? | -- | Go to Step 3 | Go to Step 4
3 | Repair the open in CKT 65. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --
4 | Inspect for an open in CKT 1550. Did you find an open? | -- | Go to Step 5 | Go to Step 6
5 | Repair the open in CKT 1550. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --
6 |

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

Is the repair complete?

--

System OK

--

7 | Use a test lamp to backprobe the blower relay connector between terminal 85 and terminal 86. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp light? | -- | Go to Step 8 | Go to Step 9
8 |

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

Is the repair complete?

--

System OK

--

9 | Use a test lamp in to backprobe the blower relay connector terminal 85 and ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp light? | -- | Go to Step 4 | Go to Step 11
10 | Repair the open or short to ground in CKT 52. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --
11 | Use a test lamp to backprobe the HVAC control assembly connector C3 between terminal C and ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp light? | -- | Go to Step 10 | Go to Step 12
12 | Inspect for an open in the HVAC control assembly connector CKT 41. Did you find an open? | -- | Go to Step 13 | Go to Step 14
13 | Repair the open in the HVAC control assembly connector CKT 41. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | System OK | --
14 |

1. Inspect the HVAC control assembly connector for a poor connection. Refer to Intermittents and Poor Connections
2. If the connection is OK, replace the HVAC control assembly connector. Refer to Control Assembly Replacement

Is the repair complete?

--

System OK

--