For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Check the blower. Does the blower run at any speed? | Go to Step 14 | Go to Step 3
3 |

1. Disconnect the power connector from the blower motor under the dashboard on the passenger side of the vehicle.
2. Turn the ignition ON.
3. Turn the blower ON.
4. Test for 12-volts on the connector. The terminal connected to the violet wire is positive and the terminal connected to the black wire is negative.

Is this voltage present?

Go to Step 4

Go to Step 5

4 | Replace the blower motor. Is the repair complete? | System OK | --
5 | Check fuse F19 in the passenger compartment fuse block. Is the fuse blown? | Go to Step 6 | Go to Step 7
6 |

1. Turn the ignition ON.
2. Use a short detector to locate a possible short in the following locations:

• | From the fuse panel to the blower speed switch

• | From the blower speed switch to the heater resistor block

• | From the heater resistor block to the blower motor

• | From the blower speed switch to the blower HI relay

3. Repair any short.
4. Replace any blown fuse.

Is the repair complete?

System OK

--

7 |

1. Turn the ignition ON.
2. Set the blower switch on 4.
3. Check the blower motor ground.

Is ground OK?

Go to Step 9

Go to Step 8

8 | Repair the blower motor ground. Is the repair complete? | System OK | --
9 | Check the motor connector with a 12-volt test light. Does the test light come on? | Go to Step 10 | Go to Step 11
10 | Repair the open in the feed wire from the resistor block to the blower motor. Is the repair complete? | System OK | --
11 | Use the 12-volt test light to check the power feed terminal on the blower speed switch. Does the light come on? | Go to Step 12 | Go to Step 13
12 | Replace the blower speed switch. Is the repair complete? | System OK | --
13 | Repair the open in the power wire from the blower speed switch to the fuse panel. Is the repair complete? | System OK | Go to Step 14
14 | Check the blower operation at speed 4. Does the blower fail to operate at speed 4? | Go to Step 15 | Go to Step 21
15 | Check fuse EF8 in the engine fuse compartment. Is the fuse blown? | Go to Step 16 | Go to Step 17
16 |

1. Turn the ignition ON.
2. Turn the blower motor switch to 4.
3. Use a short detector to locate a possible short in the following locations:

• | From the engine fuse panel to the blower HI relay

• | From the blower HI relay to the blower motor

4. Repair any short.
5. Replace the EF8 fuse.

Is the repair complete?

System OK

--

17 |

1. Turn the ignition switch ON.
2. Turn the blower motor switch to 4.
3. Check for 12-volts on the blower HI relay coil terminal from the blower speed switch terminal B3.

Is this voltage present?

Go to Step 18

Go to Step 19

18 | Replace the blower speed switch. Is the repair complete? | System OK | --
19 |

1. Turn the ignition OFF.
2. Check for opens in the following locations:

• | EF8 to the blower HI relay

• | Blower speed switch to the blower HI relay

• | Blower HI relay to ground

• | Blower HI relay to the blower motor

3. Repair any opens.

Is the repair complete?

System OK

Go to Step 20

20 | Replace the blower HI relay. Is the repair complete? | System OK | --
21 |

1. Disconnect the resistor block connector.
2. Connect one lead of a self-powered test light to any single lead on the resistor block. Use the other lead to probe each of the other 2 terminals.

Does the test light illuminate on all terminals?

Go to Step 23

Go to Step 22

22 | Replace the resistor block. Is the repair complete? | System OK | --
23 |

1. Turn the ignition to LOCK.
2. Disconnect the connector from the resistor block.
3. Connect a jumper lead from the positive terminal on the battery to any wire terminal in the connector.
4. Use a 12-volt test light to check for voltage from the corresponding wire on the blower speed switch.
5. Repeat the same test on the other wires.

Does the lamp light on all 3 wires?

Go to Step 25

Go to Step 24

24 | Replace the blower speed switch. Is the repair complete? | System OK | --
25 | Repair the open in the affected wire. Is the repair complete? | System OK | --