Extension cords, over time, can receive a lot of wear and tear. During normal use, the plug ends can become damaged for any number of reasons. As long as the extension cable itself shows no sign of disfigurement, the plugs can be replaced. New female plug ends can be purchased from most hardware and home stores. Replacing the plugs requires very little time, generally less than ½ hour. The tools needed for the repair may already be on hand in your home.
Remove all electrical power from the extension cord before performing any service to the female plug. Inspect the length of the extension cable for any signs of cracked insulation or exposed wires. If the cord is damaged, it should be replaced in its entirety with a new extension cord.
Cut off the old female plug where the cable goes into the rear of the plug. Use a pocket knife.
Remove 2 inches of the outer insulation on the extension cable with the knife. This will reveal a single black insulated wire, a single white insulated wire and a single insulated green wire.
Strip ½ inch of the individual wire insulation from the ends of each wire, with the wire strippers. This will reveal the bare copper wire underneath.
Open the new female replacement plug with the screwdriver. Generally two screws are on the face of the plug. Remove the screws and the rear of the plug will come loose. Loosen the two screws on the rear of the plug for the attached cable clamp.
Slide the wires through the cable clamp on the rear of the female plug. Do not retighten the clamp screws yet.
Terminate the individual wires from the extension cord to the colored screws on the inside of the female plug in the following order. Secure the black wire to the copper-colored screw. Attach the white wire to the silver-colored screw. Insert and tighten the green wire into the green-colored screw.
Slide the cable clamp to meet the female plug. Insert the two face screws to attach the two parts together. Push the extension cable into the rear of the plug just enough so the outer insulation is held under the rear cable clamp. Tighten all screws.