For 1990-2009 cars

A single application of the Air Conditioning Deodorizer, GM P/N 12377951, removes musty odors from the air conditioning system.

1. Turn the ignition switch to the LOCK position.
2. Set the parking brake.
3. Make sure that the cowl vent grill is clear.
4. Place an auxiliary fan in front of the vehicle.
5. Set the A/C switch to the OFF position.
6. Set the air mode to the VENT position.
7. Set the fresh/recirc lever to the FRESH position.
8. Set the temperature control to the hottest position.
9. Start the engine.
10. Set the blower speed to HIGH for 10 minutes.
11. Shake the contents of the Air Conditioning Deodorizer, GM P/N 12377951.
12. Insert the extension tube into the can nozzle.
13. Open the instrument panel (IP) compartment.
14. Push in the left and right side of the IP compartment and lower the IP compartment.
15. Remove the passenger compartment air filter from the evaporator case.
16. Wear safety goggles and latex gloves.
17. Cover the carpet area underneath the blower case and the evaporator case with a shop rag in order to collect any deodorizer liquid that may spill.
18. Insert the extension tube into the evaporator case past the mark on the tube.

With the blower still on HIGH , spray the contents of the air conditioning deodorizer over a 5 minute period with short bursts while varying the direction of the tube.

19. Turn the blower speed to the OFF position.
20. Turn the ignition switch to the LOCK position.
21. Let the vehicle sit for 5 minutes.
22. Start the engine.
23. Install the passenger compartment air filter.
24. Close the IP compartment.
25. Set the blower speed to HIGH for 20 minutes.
26. Turn the ignition switch to the LOCK position.