Troubleshooting Hints For A/C

If a vehicle has insufficient cooling and shows no error codes for the air conditioning system, then some basic checks should be made.
1. Is the blend air door operating properly and sealing correctly?
2. Does the compressor clutch engage?
3. Is the refrigerant charge low?
4. Is the blower motor working properly?
5. Is the water valve operating properly?

If the system cycles between hot and cold levels, check for:
- Foreign objects in the grille of the in-car temperature sensor or the thermistor housing.
- Proper aspirator fan operation.