Sometimes, what people bother so much about turn out to be problems whose solutions are extremely obvious. This conversely means that checks for electrical problems in cars should start at the most obvious locations; the battery being a good example. Sometimes, a case of a car failing to 'start' or something of that sort could be simply as a result of an electrical contact breakdown at the battery. Here all that is required in the name of auto electrical repairs is something as simple as filing the terminals that connect the car to its battery.
You can also perform the test yourself if you have access to a Battery Load Tester, a device which is made for the purpose. The load tester works by placing a specific amount of electrical load on the battery for a specific amount of time while monitoring the available battery voltage. The battery should be fully charged before the test in order to insure accurate test results.
Replacing Your Window Motor or Regulator: Remove the door panel. This task will vary from car to car, but typically you will have to remove some screws around the middle of the panel (such as inside the door pull) and then use a prying tool around the outside to pop out the clips on the perimeter. Sometimes you may have to remove things such as weather-stripping or door moldings as well.
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.