Aside from a dead battery or a faulty charging system, the most common electrical problems that owners are likely to encounter are burnt-out bulbs.
After bulbs, however, it’s probably a stroke of luck: electrical issues could arise in many places, from the stereo system to an electric motor for a window or a sunroof, to an electric fuel pump. Additionally, the cause could be faulty wiring, in short, there might be a defective switch or another hard-to-locate gremlin.
Bulbs, however, are probably number 1 on the replacement list because they are used so much and because there are so many of them. Most cars, for example, have at least three bulbs and usually more on each side for brakes, taillights, reverse lights, turn signals, and side marker lights. At the front, there are headlights, possibly separate high beams, frequently daytime running lights and fog lights, turn signals, parking lights, and side markers.
It’s likely that over time, at least a few of them will burn out or stop working due to corrosion or excessive jostling on rough roads.
With other electrically powered features, the cause (and solution) may not be as straightforward. For this reason, if an electrical accessory stops working, it’s a good idea to first check if a fuse protecting the circuit it’s on has blown. The owner’s manual should indicate where the fuse for a particular feature is located (usually in a side panel under the dashboard near the driver’s seat or under the hood).
If you’re handy with a multimeter that measures voltage, resistance, and other things, you might be able to diagnose some of your own electrical problems. However, because they can be difficult for professionals to find and fix, they can be even more challenging for amateur technicians to resolve.