How To Diagnose Common Chevrolet A/C Issues

Diagnosing air conditioning systems can be a fairly complicated process. This guide will shed light on common issues pertaining to air conditioning systems to help diagnose your Chevrolet.

Caution: Always wear safety glasses and gloves.

Chevrolet AC


When the air conditioning system is acting up, the compressor is the easiest place to begin. This part of the system transports refrigerant through the air conditioning system to create cool air for the vehicle.

Diagnostic Procedure:

  1. Turn your Chevy on and set the air conditioning to max cool, set the fans to the highest setting, and ensure the compressor’s clutch is engaging. Notice: Said clutch is not the pulley; it is the component in the center that engages the pulley to the compressor shaft. If the clutch is indeed engaging and disengaging rapidly, the refrigerant levels could be low.
  2. If the clutch is not engaging, check the voltage getting to the compressor with a voltmeter. If there is voltage, the clutch may be bad.
  3. If there is no voltage there may be a bad cycling switch, a blown fuse, or there may be a lack of refrigerant pressure and the low pressure cutoff switch that cycles the compressor is not being tripped.

Cool, Not Cold

Your air conditioner is set to the max cool setting and the fans are on, but the air being blown into the vehicle’s interior is only moderately cool.

Diagnostic Procedure:

  1. Check to see the cooling fans on the condenser or radiator are operating when the air conditioning is turned on.
  2. Check for any debris or dirt build-up that would restrict air from passing over the condenser. Also check the vents on the outside of the vehicle that allow the hot air from the condenser to escape to make sure they are not clogged.
  3. Check the cabin filter to make sure it is not clogged.
  4. If the system is turned on and air is not flowing into the interior of the car, the blower motor may need to be examined or replaced.


Leaks are the most common issues associated with air conditioning systems in vehicles. Refrigerant is necessary to produce cold air. Any leak, no matter the size, can be a problem for your vehicle’s air conditioning system. If pressure is low, there may be a leak.

Diagnostic Procedure:

  1. Check around all fittings to make sure they are secure
  2. Check hose manifolds on the compressor
  3. Check hoses where they are crimped into the fittings
  4. Check the front seal and O-rings that seal the pressure switches on the back of the compressor
  5. Check the Schrader valves
  6. Check for any pinholes in the condenser
  7. Check where the evaporator drains condensation