How to Replace the A/C Compressor on a Miata

by Eli Laurens

The Mazda Miata was manufactured with an optional air conditioning system, which uses a compressor to circulate freon coolant. This compressor can fail due to a lack of lubricant, malfunctioning clutch or electrical problem, requiring replacement. The average backyard mechanic can replace the compressor in a Miata in about two hours.

Step 1

Evacuate the air conditioning system by taking the Miata to a garage or oil change facility. They have professional recapturing equipment and get compensated for collecting freon.

Step 2

Disconnect the battery by turning the positive terminal in a counterclockwise direction. Store the terminal away from metal.

Step 3

Press the tension pulley arm until there is enough slack to slide the belt out from underneath the idle pulley. Release the tension pulley arm and the slack belt should come off of the compressor pulley wheel easily.

Step 4

Disconnect the freon lines by turning the line nuts counterclockwise. Store the lines away from the compressor.

Step 5

Remove the compressor by turning the mount nuts counterclockwise while holding the bolt heads with a socket wrench. Disconnect the compressor from the wiring harness by pulling the adapter plug from the compressor terminal. Slide the mount bolts out of the compressor mounts, and the compressor can be manipulated out of the engine bay.

Step 6

Replace the compressor by positioning it into the mount arms, then sliding the mount bolts into place. Secure the mount nuts by holding the bolt heads and turning the nuts clockwise. Reattach the wiring harness adapter plug to the terminal.

Step 7

Attach the freon lines to the compressor by turning the line nuts in a clockwise direction until they are tight. Wrap the belt around the compressor pulley wheel, groove side down. Press the tension pulley and slide the belt underneath the idle pulley, then release the tension pulley arm. The belt will tighten around the compressor.