Warning: the models described are equipped with pneumatic airbags. Before performing procedures in the restraint area, you must turn off power to the SRS system to prevent accidental deployment of the airbags, which could result in serious injury (see _ chapter 12).
Note: This procedure applies to the front heater fan and its electrical circuit on all models described. Some vehicles are equipped with additional heating and air conditioning systems for the rear compartment. Diagnosing these systems using conventional universal devices is not possible. If necessary, such vehicles should be sent to a proprietary or other station of the appropriate level of qualification, since in this case, diagnosing a system that has a built-in control unit is carried out using special electronic equipment.
1. Inspect the fuse contacts (with HVAC marking) and all electrical circuit connectors for the presence of corrosion deposits, as well as for connection reliability. Make sure the battery charge level is sufficient.
Note: The heater/fan relay is located in the motor housing, which is located in the passenger compartment. The fuse labeled HVAC is located in the box located on the left side of the instrument panel.
2. Place the transmission in Park, engage the parking brake, and turn the ignition key to Run. There is no need to start the engine.
3. Remove the central heating/air conditioning system cover located under the glove box, then remove the box.
4. Connect a voltmeter to the contact terminals of the heater fan motor (see illustration).
9.4 Connect a voltmeter to the contact terminals of the heater fan motor and move the speed switch through all positions
5. Move the fan switch through all positions, noting the change in voltmeter readings. A change in voltage indicates the operation of the fan speed switch.
6. If the fan does not turn on when there is voltage in the circuit, check its operation. Disconnect the wires from the motor and connect it directly to the ground loop (chassis element) and battery (through a connecting wire with a fuse). If the fan does not turn on, it means it is faulty.
7. If no voltage was supplied to the electric motor, but during the test the fan’s operation was confirmed, follow the passage of its ground wire, which has a connection in the area of the right front corner of the lower console. Make sure that the ground wire is in reliable contact with the car body element. If necessary, restore the ground loop circuit.
8. If after this the fan operation is not restored, inspect the resistor, control panel and related wiring. Perhaps the problem is caused by a failure or broken contacts of these elements.