An AC power cord
is used to bring alternating current to an appliance. Replacing a power cord is a less expensive option than replacing an entire appliance. There are many varieties of AC cords as the type of cord is dictated by the amount of electricity the appliance needs as well as the design of the plug's end.
AC is an acronym which stands for alternating current. Alternating current is generated through power cords. The current is generated in the form of electrons, which flow in one direction, then in the opposite direction. Because the electrons flow in different directions, the current is said to be alternating, hence the name, alternating current, or AC. Power cords are the means of connecting appliances and electronics to AC power sources.
In most American appliances and electronics, the AC cord has three prongs. The left prong is slightly larger than the right prong, and the bottom prong is somewhat rounded. In plugs with only two prongs, the left prong is still usually somewhat larger than the right prong. In some instances, a thin sheet of foil is attached to the area where the third prong would usually be located. The left prong and bottom prong, as well as the thin foil, are all designed to ground the cord, or protect users from electric shock by shutting down the appliance in case a wire becomes loose.
Bend the AC cord and pull on it along the entire length of the cord. If the multimeter reads zero ohms, the plug is functioning properly. If the millimeter reads high ohms or the ohms fluctuate when pulling on the cord, the AC cord is faulty and should be replaced. A fluctuating reading means that there is an open circuit somewhere within the cord.
Set the multimeter to use the resistance times 1 scale. Clip one of the multimeter jumper wires to the male plug and insert the multimeter test probe into the female plug. The male plug has prongs that stick out and the female plug will be at the opposite end of the cord.
Unplug the AC power cord
from the wall outlet and from the appliance it is powering. You may need to unscrew or unclip any cord connectors on the appliance in order to remove the plug. This will depend on the type of appliance.
Move the probe at the female plug to the other prong on the male plug if the cord read zero ohms in step 3. If the cord still reads zero ohms, the cord is in good operating condition. If the multimeter has a high ohm reading or a fluctuating reading, the cord has a short circuit and must be replaced.