Things You'll Need
Your refrigerator's built-in compressor unit functions as both a motor and a pump that moves liquid refrigerant throughout the unit. The compressor is powered by a relay box. When the relay loses power, the compressor stops working and keeps your refrigerator from staying cool. Supco RCO 3 'n 1 is a relay box that can be wired directly into your refrigerator unit's compressor. It comes in both 115- and 230-volt units to match your refrigerator's compression unit.
Unplug the refrigerator's main power cable from the nearest electrical outlet. Slide the refrigerator away from the wall, and rotate it so the rear panel is facing you. Allow 30 minutes for the refrigerator to cool down.
Remove the Phillips-head screws securing the lower panel in place. Lift the panel off the refrigerator cabinet to reveal the compressor unit.
Locate the relay box mounted to the side of the compressor. It will either be glued or taped to the compressor, or mounted to it with a couple of screws. Remove the relay from the compressor.
Cut off the black and white wires where they meet the relay box, using wire cutters. Disconnect the three wire connectors from the terminals on the compressor. Remove the relay box from the refrigerator completely.
Examine the wiring diagram on the compressor unit. The diagram will display which terminals on the compressor have positive, negative and neutral charges.
Grasp the 3 'n 1 relay box, and locate the five wires protruding from it. There are three color-coded wire plugs (red/positive, black/negative and blue/neutral) to match the terminals on the compressor, as well as two wires (red/positive, black/negative) that match the two wires protruding from the compressor.
Strip back the insulation 1/2 inch on the red and black wires protruding from the relay box, using wire strippers. Match the red wire on the relay to the red wire on the compressor, and the black wire on the relay to the black wire on the compressor. Twist each wire together until they are firmly attached. If necessary, use a pair of pliers to twist the wires together. Add wire caps to each set of wires.
Connect the red wire plug to the positive terminal on the compressor. Then connect the black wire to the negative terminal, and the blue wire to the neutral terminal. Refer to the compressor's wiring diagram for the exact location of each terminal.
Stuff the wires carefully into the refrigerator cabinet. Place the relay box inside the cabinet next to the compressor unit. Vacuum out all dust and debris from inside the refrigerator cabinet.
Replace the refrigerator's rear panel and any retaining screws.