How do I add refrigerant to my car's AC?

Adding refrigerant to a vehicle's air conditioning system requires a DIY aerosol recharge kit containing the correct refrigerant type and a pressure gauge hose assembly. First, start your car's engine, turn the air conditioning on maximum cold with the blower fan running on high, and open all doors. Second, locate the low-pressure service port under the hood, which is typically found on the thicker aluminum accumulator or suction line, and remove its protective plastic cap. Third, shake the refrigerant can well, attach the quick-connect fitting of the gauge hose firmly onto the low-side service port, and pull the trigger while gently shaking the can back and forth to allow contents to flow into the system. Fourth, monitor the gauge to ensure pressure stays within the green operating zone, and avoid overcharging. You can verify that the recharge was successful when your dashboard vents begin blowing cold air.