You can speed the tune-up process by being ready to describe what happens and when (such as whether your car hesitates when the engine is cold or when passing at highway speeds), any sounds you hear and what you feel when your car’s "illness" shows up. One caution about lower fuel economy: You should expect it to go down at least a little during the cold months, and maybe a lot. Colder temperatures make your engine and charging system work harder. In addition, winter gasoline blends have slightly less energy content than summer blends, so they don’t deliver as many miles per gallon. A tune-up won’t make Old Man Winter, or his effects, go away.
There are also electrical faults in cars that are caused by gadgets in the cars, for instance audio and video systems, which consume too much power. As mentioned earlier, in as much as the exact trouble spot can be identified, repair of electrical faults in cars becomes a 'walk in the park.' The cost of repairing electrical faults in cars varies considerably; from just a few bucks to what can turn out to be quite a fortune. It helps to ensure that these faults are rectified by the right people, and the regular mechanics may not be the ideal people here; unless they also have certifications and experience in automobile wiring.
If your vehicle's engine misfires, hesitates, stalls, gets poor mileage, is hard to start or has failed an emissions test, it clearly needs something, though a tune-up in the traditional sense might not be the cure. If you tell a repair shop your vehicle needs a tune-up, the mechanic should ask what you feel the signs are that you need maintenance before recommending any service. Just like a doctor should ask what symptoms you're experiencing, a mechanic should seek to diagnose the problem. And just as a doctor may recommend some tests, a mechanic may do the same.
Use a multi-meter to confirm that the switch is getting 12V of power. Attach the leads of the multi-meter to where the electrical wires come into the switch and set the meter to DC volts. It should read 12 volts. Trace the wiring from the switch to the motor. This is the path that a signal will travel to move your window when you press the switch. Any breaks or loose connections in this path will prevent your motor from functioning properly. Use the multi-meter to confirm that the motor is getting 12V of power.