Heating, Ventilation, and Air Conditioning

Troubleshooting

~1min read

Troubleshooting

Symptom Table

Before replacing or repairing air conditioning components, first determine whether the malfunction is related to refrigerant charge, airflow, or the compressor. Use the table below to find the cause of the problem. The numbers indicate the priority of the probable cause. Check each part in order. Replace these parts if necessary. After repair, check the entire system to make sure performance is satisfactory. Standard:
Symptom Suspected Area
No Fan Operation 1. Blower Fuse
2. Blower Relay
3. Blower Motor
4. Power MOSFET
5. Blower Speed Switch
6. Wiring Harness
No Air Temperature Control 1. Engine Coolant Reservoir
2. Heater Control Unit
Compressor Does Not Operate 1. Cooling Capacity
2. A/C Fuse
3. Compressor
4. A/C Pressure Sensor
5. A/C Switch
6. Evaporator Temperature Sensor
7. Wiring Harness
Vent Air Not Cold 1. Cooling Capacity
2. Refrigerant Pressure
3. Drive Belt
4. Compressor
5. A/C Pressure Sensor
6. Evaporator Temperature Sensor
7. A/C Switch
8. Heater Control Unit
9. Wiring Harness
Insufficient Cooling 1. Cooling Capacity
2. Drive Belt
3. Compressor
4. Condenser
5. Expansion Valve
6. Evaporator
7. Refrigerant Lines
8. A/C Pressure Sensor
9. Heater Control Unit
Engine Does Not Idle Well with A/C On 1. Engine ECM
2. Wiring Harness
No Air Flow Control 1. Heater Control Unit
No Mode Control 1. Heater Control Unit
2. Mode Actuator
Cooling Fan Does Not Operate 1. Cooling Fan Fuse
2. Blower Motor
3. Engine ECM
4. Wiring Harness

Test yourself

A quick Hyundai Kona quiz: every answer comes with an explanation and a link to the manual page.