Opens and shorts are two of the most commonly occurring problems with automotive wiring. An open occurs when there is a physical break anywhere in the circuit or indeed within an individual component forming part of the circuit. Due to this physical break, an open means that no current is able to flow, thereby either being unable to reach the load or return through the earth path to the battery. A short, meanwhile, occurs when a component or the wiring is damaged, for example, as a result of the insulation chaffing, and the electrical current in the circuit being able to find a new path back to the battery. Typically, with automotive wiring the short will occur when exposed wire(s) are able to touch each other, bodywork or a component, allowing the current to go to earth rather than take the long way , i.e. Its intended path, back to the battery.
