Examine the male and female plugs to locate the screws holding them together. Using an electrician's screwdriver, remove the retaining screws and lift off the top of each plug. Starting with either plug, identify the half through which the wire enters the plug, and feed about 3 feet of the extension cord through the opening. Repeat with the other plug.
Cut away the final 3 inches of outer insulation at both ends of the cord. Take care not to damage the insulation around the individual wires within the cord. Starting with either plug, align the end of the outer insulation with the cord grip, and then route the three wires to the terminal screws.
The white wire goes to the silver, or neutral, terminal; the black or red wire goes to the brass, or positive, terminal; and the bare metal or green-coated wire, goes to the grounding terminal. This may be colored green or marked as GND. Cut each wire to the correct length, so that the wires can reach the terminal without being stretched or bunched up.
Use a knife or wire-strippers to remove the final quarter-inch of insulation on each wire. If the exposed wire is composed of fine copper filaments, twist them together to make a stiff rod. Attach each wire to the correct terminal. Repeat with the other plug. Fit the cord into the cord grip in each plug, and check that the wires are not pinched or pulled tight.
Set the digital multimeter to measure continuity. Attach one probe to the grounding pin on one plug, and the other probe to the grounding pin on the other plug. A zero heading or a beeping sound confirms that they are correctly wired together . Make the same check on the neutral wire and then the live wire. If a test fails, check the wiring for incorrect connections and loose terminal screws. Replace the plug tops. The cord is ready for use.
