For 1990-2009 cars

Most A/C system problems can be detected by a thorough visual and physical inspection of the system and its components.

Important: The importance of this check cannot be stressed enough because proper heating and cooling depends upon adequate front air flow.

1. Check condenser to radiator seal, and rear hood seal for missing or damaged parts.
2. Check outer surfaces of radiator and condenser cores, to be sure air flow is not blocked by dirt, leaves, or other foreign material.
3. Check for kinks in hoses and lines. Also check for refrigerant leaks using an electronic leak detector.
4. Check for worn/loose drive belt or malfunctioning belt tensioner.
5. Check blower motor operation at all speeds.
6. With blower on high, check for equal distribution of air from all outlets.
7. Check operation of control mode knob and distribution of air from designated outlets.
8. Depress recirc button with blower on high. A noticeable increase in air flow and sound should occur. Indicator should light.
9. Start engine and run until it is up to operating temperature.
10. Check operation of temperature control knob and air outlet temperature from hot to cold.
11. Depress A/C button. Indicator should light. Check compressor for clutch engagement, slippage, or noise.
12. Check electric cooling fan operation and speed as determined by system temperature and pressure.
13. Turn OFF A/C. Compressor clutch should disengage.
14. If any problem is found in any of the previous steps, go to the complaint condition cause charts.