How to charge car ac with manifold gauges?

A closeup of a typical a/c manifold gauge set. The blue hoses, gauge, and valve knob represents the low pressure side of the air conditioning system, and red ones represent the high pressure side. The yellow hose in the center is designed for recharging the system with canned refrigerant or evacuating the system. read more

If you need to recharge the air conditioner in your car, connect hose on the refrigerant can to the low pressure charging port on the refrigerant line on your car. Crank your engine and turn the AC on high cool, high fan, then open the valve on the refrigerant can until you hear refrigerant passing through the hose. read more