Problems with a car's electrical wiring can manifest as equipment malfunctions, blown fuses, burning smells or unusual battery drain depending on the wires affected and the actual problem. A piece of electrically powered equipment may also cease to function entirely if there is a wiring problem that affects it.
Electrical wiring problems can be difficult to diagnose, as symptoms of other electrical problems often co-occur with the signs of a wiring issue. For example, a blown fuse can cause electrical equipment connected to that fuse to cease functioning until it is replaced, but the blown fuse itself may be symptomatic of a short circuit in the car's wiring. Tracking down problems with wiring is therefore often a process of elimination where other potential causes for an issue must be ruled out until only the wiring remains.
There are three types of typical wiring faults found in automobiles, and it is often possible to use an electric meter to distinguish the most likely type of fault. An open circuit condition occurs when the wiring is broken or disconnected from the electrical system, though many failures of this type involve bad connectors or circuit boards as well. A short circuit involves an undesired electrical connection in the system that can cause wires to melt or fuses to blow, which can result in a subsequent open circuit fault if a wire burns completely through. Finally, ground faults are similar to short circuits but generally do not cause the same level of damage as the electrical energy flowing through the wire is dissipated by the grounding object.