GMC spark plug wires are part of the ignition system of your vehicle, contributing to the process that brings spark to the engine to ignite the fuel and oxygen mixture in the combustion chambers. Forming the connection that carries the high voltage spark from the distributor to the spark plugs, the GMC spark plug wires are quite important to the process. GMC spark plug wires are equipped with a jacket of heavy insulation to contain the high voltage they transmit, and protect against moisture contamination. A rubber boot at the end of each of the GMC spark plug wires forms the connection to the spark plug, fitting tightly on its end to transmit the high voltage spark that it requires to ignite the fuel and air in the combustion chamber. The transmission of this high voltage spark will gradually deteriorate the GMC spark plug wires, making it necessary to replace them periodically. Over time, the heat of the engine or exposure to vehicle fluids can degrade the insulated jacket of the GMC spark plug wires, allowing moisture to infiltrate and transmission of the high voltage spark to become much less efficient. The rubber boots can become loose and cracked over time as well, creating a poor connection. If the GMC spark plug wires have developed such damage and wear, the vehicle is likely to show symptoms such as engine misfire, a loss of engine power, and excess exhaust emissions. Our user-friendly online catalog carries a selection of quality replacement GMC spark plug wires to keep your engine at its best. Our great prices and expert customer service will make ordering your GMC spark plug wires fast and easy whether you use our secure site or our convenient toll-free phone line.