Operation CHARM: Car repair manuals for everyone.

Troubleshooting Points

- When inspecting the heater or air conditioner, warm up the engine before each operational check. The engine coolant temperature must be 40° C {104 °F} or higher.
- The air conditioner is composed of an electrical system as well as a refrigerant system. Because some refrigerant system components require the evacuation of refrigerant gas before replacement, inspect the electrical system first.