1. Low Refrigerant: This is the most common cause. Refrigerant leaks over time, and without enough, the system can't cool properly. You'll need a professional to diagnose and recharge the system, as it requires specialized equipment and knowledge to handle refrigerants safely. Do not attempt this yourself. A leak detection is necessary to find and repair any leaks before recharging.
2. Compressor Issues: The compressor is the heart of the AC system. Problems include:
* Compressor clutch malfunction: The clutch engages the compressor. If it's not engaging, the compressor doesn't run. This can be due to a faulty clutch relay, low refrigerant, or a bad compressor clutch itself.
* Compressor failure: A seized or worn-out compressor needs replacement. You'll likely hear unusual noises if the compressor is failing.
3. Condenser Issues: The condenser is the radiator-like component that releases heat. A clogged condenser (from debris) or a damaged condenser (leaks) will prevent efficient cooling.
4. Evaporator Issues: Located inside the vehicle, the evaporator cools the air. A restricted airflow through the evaporator (due to a clogged cabin air filter, dirty evaporator fins, or a blocked drain) or a damaged evaporator will reduce cooling.
5. Blower Motor Issues: This is responsible for circulating air. If the blower motor is weak or not working, you won't get any air, cold or otherwise. Check the blower motor fuse and relay.
6. Electrical Issues: Several electrical components control the AC system. Problems could include:
* Blown fuses or relays: Check the relevant fuses and relays in the fuse box.
* Wiring problems: Damaged or corroded wiring can disrupt the system.
* Pressure switch issues: These sensors monitor the refrigerant pressure and can prevent the compressor from running if pressure is too low or high.
7. Expansion Valve/Orifice Tube Issues: These regulate refrigerant flow. A clogged or faulty expansion valve/orifice tube will impair cooling.
Troubleshooting Steps (Some require basic mechanical knowledge):
1. Check the fuses and relays: Consult your owner's manual to locate and check the fuses and relays related to the A/C system. Replace any blown fuses.
2. Inspect the cabin air filter: Replace it if dirty; this improves airflow.
3. Listen for compressor sounds: With the A/C on, listen near the compressor. A clicking sound might indicate a clutch issue. A grinding sound suggests a failing compressor.
4. Check the condenser for debris: Inspect the condenser (in front of the radiator) for debris blocking airflow. Clean it gently if needed.
What to do:
* Start with the easy checks: Fuses, relays, and cabin air filter are the easiest to check and replace.
* Professional Diagnosis: If the problem persists, take your Durango to a qualified mechanic specializing in automotive air conditioning. They have the tools and expertise to diagnose the issue accurately and perform the necessary repairs, including refrigerant recharging and leak detection.
Ignoring a failing AC system can lead to further damage and higher repair costs. Professional diagnosis is recommended for accurate and safe repair.
