Is the fan turning (do you hear it)? If it's blowing, but not passing the blend door, then that would describe why it doesn't deliver air to the passenger compartment.
Poor Heater System Performance
CAUTION Check all fluid levels and adjust as needed, before operating vehicle for extended periods at idle.
- Start the engine.
- Idle the engine until the thermostat opens (upper radiator hose will be hot) Is the engine at normal operating temperature (approx. 200° F)? If yes, go to the next step. If no, go to step 16.
- Set the mode selector to FLOOR mode.
- Set the heater control selector to the warmest temperature setting.
- Set the blower speed the lowest setting.
- Carefully feel the inlet and outlet heater hoses at the heater core. Is the inlet heater hose significantly hotter than the outlet heater hose? If yes, go to step 14. If no, go to the next step.
- Set the mode selector to PANEL mode.
- Select the maximum blower speed.
- Select the warmest temperature setting.
- Place a thermometer into the center I/P PANEL air outlet and affix a second thermometer to the heater core outlet heater hose.
- Record the temperature at the center I/P PANEL air outlet and at the heater core outlet heater hose. Are the two temperature readings about equal? If yes, go to the next step. If no, go to step 13.
- Inspect and repair the cowl, cowl area, recirculation door, and the HVAC evaporator/heater core case for cold air leaks. Repair any problems found, go to step 17.
- Inspect the temperature door operation. Repair any problems found, go to step 17.
- Turn OFF the engine. Back-flush the heater core. Start the engine. Select the FLOOR mode and the lowest blower speed. Select the warmest temperature setting. Feel the temperature of the inlet and outlet heater hoses at the heater core. Is the inlet heater hose feel significantly hotter than the outlet heater hose? If yes, go to the next step. If no, go to step 17.
- Replace the heater core. When the repair is completed, go to step 17.
- Check for low engine temperature problems, Repair or replace as needed, go to step 17.
- Operate the system in order to verify the repair. If the system operates properly, the repair is complete. If the heater still does not work properly, repeat the entire procedure.
Insufficient Defrosting
CAUTION Check all fluid levels and adjust as needed, before operating vehicle for extended periods at idle.
- Start the engine, select the DEFROST mode, and select the maximum blower speed. Does sufficient air flow from the defroster outlets? If yes, go to the next step. If there is insufficient airflow, go to step 9.
- Measure the engine operating temperature. Does the engine reach normal operating temperature (approx. 200° F)? If yes, go to the next step. If the engine does not reach normal operating temperature, go to step 7.
- Select the minimum blower speed. Select the warmest temperature setting. Carefully feel the inlet and outlet heater hoses at the heater core. Is the inlet heater hose significantly hotter than the outlet heater hose? If yes, go to step 10. If the hose temperature feels approx. the same, go to the next step.
- Test the operation of the A/C compressor clutch. Does the A/C compressor clutch engage? If yes, go to step 6. If the compressor clutch does not engage, go to step 5.
- Inspect A/C compressor clutch and controls. Repair or replace as needed, go to step 13.
- Determine if the A/C system is operating within specifications. If yes, go to step 8. If no, go to step 11.
- Check the low engine temperature problem. Repair any problems found, go to step 13.
- Inspect for correct operation of the recirculation door. If the door is operating correctly, go to step 13. If the door is not operating properly, go to step 12.
- Check air delivery system. Repair any problems found, go to step 13.
- Check the heater core for blockage. Repair or replace as needed, go to step 13.
- Check A/C performance. Repair or replace as needed, go to step 13.
- Repair the recirculation door concern. When the repair is complete, go to step 13.
- Operate the system in order to verify the repair. If the system is operating properly, the procedure is complete. If the system is still not providing proper defrosting, repeat the entire test.
Noise from Blower Motor
- Inspect the air inlet grille for debris. If the grille has debris, go to step 7. If the grille is clear, go to the next step.
- From inside the vehicle, close all vehicle doors and windows, turn ON the ignition, with the engine OFF, and cycle the blower motor through all speeds in order to determine where and when the noise occurs. If noise is heard during the blower operation, go to step 3. If there is no noise, go to step 10.
- Inspect for excessive vibration at each blower motor speed by feeling the blower case. If there is vibration, go to step 5. If no vibration is present, go to the next step.
- Listen to the blower motor at each blower speed. Is the blower motor making a squeaking or chirping noise? If yes, go to step 8. If no noise exists, go to step 10.
- Remove the blower motor, and inspect the blower motor and impeller for deposits of foreign material. If there is debris, go to step 7. If there is no debris, go to the next step.
- Inspect the blower motor impeller for cracked blades, loose impeller retainer, or improper impeller alignment. If any of these conditions exist, go to step 8. If none of these exist, go to step 9.
- Remove the foreign material, go to step 10.
- Repair or replace blower motor or impeller as needed, go to step 10.
- Install the blower motor, go to step 10.
- Operate the system in order to verify the repair. If the condition has been corrected, the repair is complete. If noise still exists, repeat the entire procedure.
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