Depleted refrigerant levels cause warm air to blow out through your air conditioning vents. The process for refilling the 2002 Nissan Altima's air conditioning system mirrors the process used for checking and adjusting your tire pressure. Use a pressure gauge to determine the current level of refrigerant in the lines. If the level reading is low, add refrigerant to the system until the gauge shows that it is full.
Connect the hose in the air conditioning recharge kit to the fill port found on top of the tube connecting the compressor to the evaporator. Remove the cap on the fill port so you can connect the hose. Of all the accessories connected to the serpentine belt, the compressor is the one closest to the front of the vehicle. The evaporator looks like a small radiator. Before connecting the tube, ensure it is secured to the can of refrigerant. If necessary, follow the instructions included with the recharge kit to connect the canister to the hose.
Start the Altima's engine and turn on the air conditioning. Check the pressure of the system using the gauge in the recharge kit. The required pressure varies depending upon the current ambient air temperature. The needle on the gauge should point to the current outside air temperature. If it's lower than that, open the release valve slowly on the canister of refrigerant, allowing the needle on the gauge to climb until it points to the current outside air temperature.
Close the valve and disconnect the recharge kit from the Altima's fill port, replacing the cap you removed in Step 1.
