Attach the leads of the multi-meter to where the electrical wires come into the motor. Again, set it to DC volts and it should read 12 volts. Look for any interrupted voltage caused by a loose connector or corrosion. If there are any loose or corroded connections in the circuit they will disrupt the signal and cause your window to malfunction. Fix the connector or corroded areas. Push any connectors or wiring harnesses together tightly, and clean any corrosion away with a wire brush or similar tool. Test the window again. If your problem was in the circuitry and is now fixed, then your window should freely roll up and down without any restrictions or delays.
Assuming that the battery is known to be good, then the next item to check is the battery terminals - the actual points at which the battery is connected into the electrical system. It is very important that these connections are clean and tight. This simple thing is often overlooked as a source of trouble, and is also a frequent cause of such trouble. Visually inspect the terminals, and clean andor tighten them if needed. To clean, use a small, stiff wire brush or a terminal cleaner which is made for the purpose.
A dirty or clogged engine air filter is more likely to reduce acceleration than fuel economy, according to tests conducted by the EPA. Because filters get dirty gradually over time, you might not notice a small but steady loss of performance until your car is accelerating like a turtle. But if you haven’t changed the filter in a couple of years (or sooner in areas that have a lot of soot in the air), that could be part of the problem.
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.