Air conditioning problems in 2013–2018 Nissan Altimas can be frustrating, particularly in hot weather. However, with some basic troubleshooting and repair skills, you can address many common issues. Below is a guide to help you diagnose and fix air conditioning problems in these vehicles.

 
Perform a Visual Inspection
 

1. • Check for Leakage: Look for signs of refrigerant leaks under the car or around A/C components such as hoses, fittings, or the compressor.
   • Inspect the Serpentine Belt: Ensure the belt driving the A/C compressor is intact and tight. Replace it if frayed or broken.

 
Check the Refrigerant Level
 

1. • Use a Manifold Gauge Set: Connect a manifold gauge set to the high and low-pressure ports to check the level of refrigerant. These ports are typically blue (low side) and red (high side).
   • Recharge the System: If the refrigerant level is low, add the correct type and amount specified in the vehicle's service manual. Be cautious as overcharging can damage the system.

 
Test the A/C System
 

1. • Turn on the Air Conditioning: Set the air conditioning to its maximum setting and check if cold air is coming from the vents.
   • Listen for Compressor Activation: The engine should load slightly, and you may hear a clicking sound when the A/C clutch engages.

 
Inspect Electrical Components
 

1. • Check Fuses and Relays: Locate the A/C fuse and relays in the fuse box and check if they're functional. Replace any faulty components.
   • Examine Wiring and Connectors: Look for frayed wires or loose connectors around the A/C system, repairing or replacing as needed.

 
Test the Blower Motor
 

1. • Adjust the Blower Speed: Test different speeds to ensure the blower motor is functioning at full capacity.
   • Replace the Blower Motor Resistor: If the blower works only at certain speeds, the resistor could be defective.

 
Service the Cabin Air Filter
 

1. • Locate and Remove the Filter: Usually found behind the glove compartment, remove the cabin air filter for inspection.
   • Replace if Dirty: A clogged filter can reduce airflow and cooling efficiency. Replace it if necessary.

 
Consult a Professional Mechanic
 

1. • Seek Expert Help: If these steps don't resolve the problem, the issue may be more complex, such as a faulty compressor or expansion valve. A professional mechanic can diagnose and repair such components.

By following these detailed steps, you can address common air conditioning problems in 2013–2018 Nissan Altimas. Remember that maintaining your A/C system and addressing small issues early can prevent more significant problems later on.