Standard Procedure - A/C Evaporator Cleaning

When equipped with A/C, some vehicle operators may experience a musty odor from the Heating, Ventilation, and Air Conditioning (HVAC) system, primarily at start up in hot and humid climates. This odor may be the result of microbial growth on the HVAC unit air filter. During normal A/C system operation, the filter accumulates dirt, organic debris, and fungal spores. When rain or mist mixes with the dirt on The filter, bacteria and fungal growth progresses and odor may result.

If the vehicle operator experiences a musty odor when operating the A/C system,

1. Change the HVAC air filter.
2. Remove the cowl panel cover. Refer to COVER, COWL PANEL, REMOVAL AND INSTALLATION .
3. Clean any dirt and debris that may be present at the HVAC fresh air inlet and the cowl plenum.

If the odor persists, perform the following procedure.

1. Remove the cowl panel cover. Refer to COVER, COWL PANEL, REMOVAL AND INSTALLATION .
2. Clean any dirt and debris that may be present at the HVAC fresh air inlet screen and at the top of the cowl panel.
3. Install the cowl panel cover. Refer to COVER, COWL PANEL, REMOVAL AND INSTALLATION .
4. Raise and support the vehicle.
5. Inspect the evaporator drain hose for foreign material that may be blocking the drain and repair as necessary.
6. Once drain operation has been verified, temporarily pinch the drain hose closed using an appropriate pair of heater hose pliers.
7. Remove the support and lower the vehicle.
8. Place a protective cover over the driver and front passenger side floor and seating areas.
9. Remove the blower motor. Refer to MOTOR, BLOWER, REMOVAL AND INSTALLATION .
10. Remove and discard the cabin air filter. Refer to FILTER, CABIN AIR, REMOVAL AND INSTALLATION .
11. Clean any dirt and debris that may be present inside the HVAC housing through all readily accessible areas inside of the HVAC housing. If necessary, use a vacuum with a small flexible hose, and take caution not to damage the fins of the A/C evaporator.
12. Using PSE Flex Spray Delivery Tool 534-62637 or equivalent, completely coat the entire surface of A/C evaporator with three bottles of Mopar® Cooling Coil Cleaner through the blower motor and filter openings. Be sure to use all of the coil cleaner in each container.
13. Allow the vehicle to sit for 30 minutes.
14. Raise and support the vehicle.
    WARNING:

    Excess cooling coil cleaner will drain from the evaporator housing when the pliers are removed from the evaporator drain hose or tube. Always use eye protection, rubber gloves and protective clothing. Avoid continuous breathing of vapors from evaporator coil cleaning fluid. Avoid contact with skin and eyes. Failure to follow these instruction may result in possible serious or fatal injury.

15. Remove the previously installed heater hose pliers and allow excess coil cleaner to drain from the HVAC housing.
16. Remove the support and lower the vehicle.
17. Refill the three empty coil cleaner bottles with clean tap water.
18. Using PSE Flex Spray Delivery Tool 534-62637 or equivalent, completely rinse the entire surface of A/C evaporator with the three bottles of clean tap water through the blower motor and filter openings. Be sure to use all of the water in each container.
19. Install the blower motor. Refer to MOTOR, BLOWER, REMOVAL AND INSTALLATION .
20. Install the cabin air filter cover, without a filter. Refer to FILTER, CABIN AIR, REMOVAL AND INSTALLATION .
21. Disconnect the wire harness connector from the A/C compressor to disable compressor operation. Refer to COMPRESSOR, A/C, REMOVAL AND INSTALLATION .
22. Start the engine
23. Adjust all the windows so they are open approximately 8 mm (0.5 in.).
24. Set the A/C heater controls to the following:
    • air distribution to Panel and Recirculation mode
    • temperature to full heat
25. Allow the vehicle to run for 20 minutes.
26. Turn the engine off.
27. Raise and support the vehicle.
28. Inspect the evaporator drain hose for foreign material that may have blocked the drain during evaporator coil cleaning and repair as necessary.
29. Once drain operation has been verified, temporarily pinch the drain hose closed again using an appropriate pair of heater hose pliers.
30. Remove the support and lower the vehicle.
31. Remove the blower motor. Refer to MOTOR, BLOWER, REMOVAL AND INSTALLATION .
32. Remove the cabin air filter cover. Refer to FILTER, CABIN AIR, REMOVAL AND INSTALLATION .
33. Using PSE Flex Spray Delivery Tool 534-62637 or equivalent, completely coat the entire surface of A/C evaporator with one bottle of Mopar® Cooling Coil Coating through the blower motor and filter openings. Be sure to use all of the coil coating in the container.
    NOTE:

    Be sure to thoroughly clean out the spray delivery tool with warm water once coil coating is complete to prevent damage to the tool.

34. Refill the empty bottles with clean warm tap water and completely rinse out the PSE Flex Spray Delivery Tool 534-62637, or equivalent.
35. Allow the vehicle to sit for 30 minutes.
36. Install the blower motor. Refer to MOTOR, BLOWER, REMOVAL AND INSTALLATION .
37. Install a new cabin air filter and the cover. Refer to FILTER, CABIN AIR, REMOVAL AND INSTALLATION .
38. Raise and support the vehicle.
    WARNING:

    Excess cooling coil coating will drain from the evaporator housing when the clamp, cap or plug is removed from the evaporator drain hose or tube. Always use eye protection, rubber gloves and protective clothing. Avoid continuous breathing of vapors from evaporator coil sealing fluid. Avoid contact with skin and eyes. Failure to follow these instruction may result in possible serious or fatal injury.

39. Remove the previously installed pliers from the evaporator drain hose and allow excess coil coating to drain from the HVAC housing.
40. Remove the support and lower the vehicle.
41. Start the engine
42. Adjust all the windows so they are open approximately 8 mm (0.5 in.).
43. Set the A/C heater controls to the following:
    • air distribution to Panel and Recirculation mode
    • temperature to full heat
44. Allow the vehicle to run for 20 minutes.
45. Turn vehicle off.
46. Remove the protective covers from the driver and front passenger side floor and seating areas.
47. Connect the wire harness connector to the A/C compressor. Refer to COMPRESSOR, A/C, REMOVAL AND INSTALLATION .
48. Verify proper heating and A/C system operation.