Air Conditioner Troubleshooting
Test Fuses Step 2 - With the engine "ON" and the A/C turned to the coldest setting with high fan speed the compressor should be operating, on older models a clutch is used to engage the compressor which is easy to see. (Note: This can take up to 1 minute to come on after the engine is started.) If the system is low on refrigerant it could cycle on and off, making a ticking noise. If the compressor clutch doesn't engage attach a pressure gauge or recharge kit to the low pressure side port to inspect system pressure readings. Please visit - AC System Recharge
Compressor Clutch Rotating
Air Conditioner Gauge Set Step 3 - If the level of refrigerant is low in the system it will not cool sufficiently. Please visit - AC System Recharge
A/C Recharge Kit Step 4 - If the state of charge is sufficient and the compressor will still not engage, the electrical system must be checked. With the engine and system still "ON" use a test light and check for power at the compressor, if power is present and the compressor is not working replacement is needed. If no power is observed proceed to the next step.
Air Conditioner Compressor Step 5 - Trigger power to the compressor is supplied by a relay or control unit, locate and test the relay, testing a climate controller is a little more difficult and requires a wiring diagram. Please visit - Relay Testing
Testing Air Conditioner Relay Step 6 - The A/C system must be able to exchange the heat at the condenser or the system will not work, or work poorly, the most common cause for this condition is engine overheating which can be caused by a plastic bag lodged in the condenser. It's also a good idea to use a garden hose to force water backward through the radiator area, this will help remove road grime from the cooling fins of the condenser and radiator. Please visit - Engine Overheating
Coolant Leak Step 7 - If a temperature blend door actuator is not functioning properly it will cause warm air from the heater to mix with cold air from the air conditioner. Start your car and allow the engine idle, turn the blower motor speed on low speed, switch the temperature control from warm to cold while your ear is close to a dash vent. An audible noise should be heard as the door moves inside the heater box from open to closed position. If not, suspect a shorted servo actuator motor or a vacuum leak on older vehicles. Please visit - Bend Door Actuator Replacement
Blend Door Actuator Step 8 - An electric blower motor forces air throughout the ventilation system, if this motor stops working no air will be exhausted from the vents. Please visit - Blower Motor Testing
Blower Motor Step 9 - Most vehicles are equipped with a cabin air filter which can clog causing the air flow to be restricted or stop. Please visit - Cabin Air Filter Replacement
Replacing Cabin Air Filter Best Practices
- Service your A/C system about every three years, activate the system periodically to keep components lubricated.