When you pop the hood and look at the complicated mechanical devices called engines, you notice right away there's plenty of wiring. In fact, the wires seem to snake around the engine in a complex configuration that makes little sense to anyone who is not a mechanic. Auto engines have plenty of electrical configurations that are critical to their smooth operation. The fact is that when a car experiences problems, it could easily be an electrical problem as much as it could be a mechanical problem. Any qualified mechanic needs to be familiar with both mechanical and electrical problems in order to be efficient at his or her job. That means a mobile car mechanic must be prepared to complete a variety of repairs including those related to the electrical systems.
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.
Battery: this invention has made the complete car electric system possible. From the old heavy and unreliable ones to today's modern batteries, it's something that a car can't go without. In the invention of the batteries lay the seeds of today's modern electric-cars. Spark plug: today it's an usual item in car mechanics. But think of the people that invented it!! Lighting the fuel-air mix with an electric spark, simply amassing. How great it is, proves the fact that the principle is unchanged ever since. Every invention on the car has it's purpose and, in mechanical terms,it's own beauty. Ranking of this kind doesn't neglect all of the other marvels on the car, on the contrary. The genius in these 5 inventions is that they stayed basically unchanged for all of these years giving the driver comfort, safety and reliability
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.