With other electrically powered features, the cause (and the fix) may not be so simple. Because of that, if any electric accessory stops working it's a good idea to first check whether a fuse that protects the circuit it's on has blown. The owners manual should show where a fuse for a particular feature is located (usually in a side panel below 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 may be able to diagnose some of your own electrical problems. However, because they can be difficult for professionals to find and fix, they might be even harder for amateur technicians to solve.
"Heat kills car batteries," according to John Banta, a Consumer Reports project leader and part of the team that tests batteries for the magazine. "Many times in cold climates, your battery fails to start your car on a below-freezing day. The reason this happens is that the heat of the past summers has weakened your battery. When you use it in the cold, the starter requires more electrical current to turn over the cold engine with its thickened oil." Leaving your car parked or stored for long periods of time can also lead to a dead battery that you will need to recharge before heading out for a drive.
The charging system will normally consist of two major components: An Alternator which actually supplies the necessary electrical current in order to charge the battery, and a Voltage Regulator. The latter insures that the system does not overcharge the battery, and that the correct system voltage is maintained. Most vehicles produced within the last 20-30 years use a voltage regulator which is an integral part of the alternator itself. This article assumes that your vehicle uses this type of alternator.
Seeking the Elusive Electrical Problem. Many times electrical problems are the most elusive, because they can occur intermittently. For example, the car engine may not work properly, but only after the engine warms up. Or the ignition works randomly. Perhaps the engine cuts out without notice while cruising down the highway. Then again, your car might have a faulty alternator or a defective wire.