Ground (Earth)

In a motorcycle's electrical system, ground (British: earth) is the common return path through which current flows back to the battery. On almost all modern bikes the battery negative terminal is grounded, connected to the frame and engine by a thick cable.

Many components use the frame or engine as part of their circuit, so a corroded or loose ground connection can cause strange faults: dim lights, flickering gauges, slow cranking or sensor errors that look like more serious problems.

When chasing an electrical gremlin, check the main ground cable and its contact points first. Clean them to bare metal, tighten them and protect them with a little dielectric grease.