A number of electrical accessories in the vehicle incorporate relays on the transmission of electrical signals to the components, and if the relay is faulty, the related component is not functional. Some relays are mounted in several areas; the relays on the firewall are representative of relays found throughout the vehicle. When an actuating relay is thought to be bad, then the relay can be disconnected and taken to a dealer service department or a repair shop, and if determinative the relays are needed are bad then the unit must be replaced.