: 1024x1325 px
: July 2, 2018
The test procedure is quite simple. Set the meter to read DC volts, and set the correct range if needed. Some meters will select the correct range automatically. Nearly all meters will come with instructions on how to set them to read DC volts. Next, connect the meter across the vehicle battery, positive (+) to positive (+) and negative (-) to negative (-). With the engine running at a moderate idle - say 1200 to 1500 RPM, the meter should read approximately 13.8 to 14.8 volts and be steady. If the reading is substantially outside these figures and all other items mentioned have been tested and verified good, then the alternator is likely defective.
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.