Is the system completely empty if so you will need a set of A/C gauges and 37 oz of R134A if the vehicle is not equipped with rear A/C and if it does have rear A/C then it will require 67 oz of R134A freon. Then hook the red hose up to the high side port and the blue hose to the low side port and freon to the yellow hose. Then start your vehicle and turn A/C on full. After that you will want to open the low side knob on your gauges and see if the compressor clutch will kick on. it might kick on and off alot in the beginning until the system has enough freon in it to keep the low pressure switch from turning the compressor off. For when you are charging it you need to google an ambiant temprature chart for R134A systems so that you know what your gauges should read when the system is full.