How to Retrofit Air Conditioning in a Nissan Sentra

Take your Nissan Sentra to a mechanic to recover the R12 refrigerant out of the air conditioning system. A license and special equipment are needed to do this. Because R12 refrigerant is expensive, many mechanics will do the job for free.

Look for the Low Pressure Side connector port. In most year models, it is along the firewall on the passenger side. Take off the black cap marked L. You must retrofit the system if you see a screw-type connector valve. If you see a quick connect valve, the system already is R134 compatible.

Wipe the connector valve off with a clean towel. This ensures that the retrofit connector properly adheres to the valve. Put the longer adapter from the automotive retrofit kit onto the port. Tighten it using an adjustable wrench. Place the blue cap from the retrofit kit onto the adapter. This keeps dust out of the system and helps to keep refrigerant in the system.

Find the High Pressure Side service port. This is located near the Low Pressure Side service port. Remove the red cap marked H or HIGH and wipe the port off with a towel.

Place the shorter adapter onto the port. Twist it using an adjustable wrench until it is securely fastened to the port. Place the red cap from the retrofit kit onto the adaptor.

Fill out the necessary information on the retrofit sticker using a permanent marker. You have to stick this to the inside of the hood where it can be seen easily by anyone who works on your vehicle.

Recharge the air conditioning system. See the related eHow titled "How to Recharge Air Conditioning with Freon in a Nissan Sentra."