When preparing for the troubleshooting or testing of refrigerator compressor circuits, the identification of the common, start and run wiring terminals is of utmost importance. Manufacturers usually color-code compressor terminal wiring in their products, but if a schematic is not available to cross-reference the colors, they can be identified by their location on the compressor terminal bus. You can identify and verify the common, start and run wires with basic do-it-your skills and a screwdriver.
Remove the refrigerator electrical plug from its outlet.
Remove the compressor access panel screws, using a Phillips screwdriver. The panel is located at the lower rear of the appliance.
Locate the compressor terminal bus. The bus has several wires of various colors connected to it. Typically, the common terminal is on the top of the bus, the run is on the right-hand side and the start terminal is on the left.