The ignition system is comprised of many components that are responsible for starting the vehicle’s engine. The rotor arm is controlled and turned by a gear, making the metal ends come into contact with the interior electrical parts. This action sparks each of the spark plugs, which then starts the internal combustion engine. Frequent use and general wear and tear can cause rotor arms to become less effective over time. If you suspect you need a replacement, you’ve come to the right place! You can use our reg look up tool to find a low priced rotor arm for your vehicle.