How to Add Air Conditioning to a Mazda Miata

by David McGuffin

Refilling the refrigerant on your Mazda Miata is a relatively easy job that can be done by even the novice do-it-yourself mechanic. A refrigerant recharge kit, available at most auto-parts stores, is the only tool needed to complete the job. It is advisable to obtain a recharge kit that has a low pressure gauge, so that you know when your car's air conditioning system is full. If you can find a kit with both high and low pressure gauges, then you will be able to refill your refrigerant according to your vehicle's pressure ratings, even more accurately.

Open the hood on your Mazda Miata and locate the high and low side pressure fittings for your air conditioning system. Locate the compressor, which has the air conditioning belt attached to it via a pulley. Between the compressor and the accumulator is a 16 millimeter valve marked with an upper-case "L," indicating low pressure. Locate the 13 millimeter high-pressure fitting, which is situated between the accumulator and the condenser, which has the appearance of a smaller version of your radiator grill.

Prepare the refrigerant recharge kit by screwing in the hose to the can, which should puncture, when the hose is tight enough. Bleed the air out from the hose by slowly twisting the refrigerant release valve until you hear a "whoosh." This signals that the air is properly expelled.

Screw the hose fitting onto the low side fitting on your Miata. Turn on your car and crank the air conditioning. Twist the valve on the recharge kit and allow the car to run until the air conditioning is blowing out cold air again.

Watch the low pressure gauge on your recharge kit: It should read between 25 and 45 psi (pounds per square inch) when the car is full. If you have a high pressure gauge, the reading should measure between 225 and 250 psi. Mazda Miata models manufactured between 2001 and 2004 all hold 14.00 ounces of R134A refrigerant. Models manufactured between 1999 to 2000 hold 20.00 ounces. Models made between 1994 and 1997 hold 21.00 ounces. Previous years utilize R12 (also known as freon or CFC-12) refrigerant, which is no longer commercially available, however, it can be refilled by professional mechanics. Alternatively, if you have an older Miata that uses R-12 refrigerant, you can also have it retrofitted to use R134A refrigerant.

Items you will need

About the Author

David McGuffin is a writer from Asheville, N.C. and began writing professionally in 2009. He has Bachelor of Arts degrees from the University of North Carolina, Asheville and Montreat College in history and music, and a Bachelor of Science in outdoor education. McGuffin is recognized as an Undergraduate Research Scholar for publishing original research on postmodern music theory and analysis.

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