How do you know if the window switch is bad or the window motor?

To determine whether the window switch or the window motor is faulty, you can perform a simple test. First, try operating the window using the switch; if the window does not move but you hear a clicking sound from the switch, the motor might be bad. Next, if you have access to a multimeter, you can test for voltage at the motor connector when the switch is activated; if there’s voltage but the motor doesn’t work, the motor is likely the issue. Conversely, if there's no voltage at the motor connector, the switch may be defective.