Your car’s ground wire, also known as a “ground cable” or “ground strap,” is perhaps the single most important wire in its entire electrical system. Think of the ground wire or cable as your electrical system’s foundation, the bridge over which all electrical flow must tread. A bad ground connection will ruin your electrical system’s day, which makes establishing a good one an extremely high-priority project.
This is one of the more obvious signs of a bad ground, manifesting in much the same way as a loose battery cable or a dead battery. When you attempt to start your car, you may hear a single click or a rapid tapping; this is the sound of the starter’s solenoid opening or closing, or the sound of the starter’s Bendix drive moving. The solenoid requires a certain amount of voltage to operate; if the ground is bad, then the solenoid will function, but the starter motor will absorb all of the current flow and shut the solenoid off.