Extension cords damage easily during use. The damage can occur at the plugs located at the ends of the cord or anywhere along its length. You can repair an extension cord with the proper tools and parts. Wiring the replacement parts correctly ensures that the repaired cord will not create a short circuit, which can trip breakers or cause a fire.
Cut the damaged plug or section from the extension cord with a pair of wire cutters.
Remove the screws from the back of the replacement plug with a Phillips screwdriver. Pull the two pieces of the plug apart. Loosen the two cable clamp screws on the back piece of the replacement plug with the Phillips screwdriver.
Slide the cut end of the extension cord through the cable clamp. Push the back piece of the replacement plug onto the extension cord. Push the cut end of the cord into the front section of the replacement plug. Mark the back edge of the replacement plug location on the extension cord with a permanent marker. Remove the front piece of the replacement plug from the end of the cord.
Cut the sheathing, roughly 3/4 inch, of the extension cord on the mark made by the permanent marker, with a utility knife. Do not cut into the interior wiring while cutting the sheathing. Pull the sheathing from the end of the extension cord. Spread apart the exposed wires.
Remove 1/2 inch of coating from each wire with a pair of wire strippers.
Loosen each terminal screw in the front half of the replacement plug with a Phillips screwdriver. Connect the green coated wire (ground) to the green screw. Connect the white coated (neutral) wire to the silver screw. Connect the black coated wire (hot) to the brass screw.
Slide the two halves of the replacement plug together. Tighten the screws to lock the piece together. Tighten the cable clamp screws.
Plug in the extension cord. Disassemble the replacement plug and check the connections if the cord feels hot or the breaker immediately trips.