How to perform continuity testing
You need to perform a continuity test to ascertain whether or not a switch has failed. A continuity test will determine if a continuous electrical path flows through a switch.
If a switch has continuity it should be working, but no continuity indicates that the electrical path is broken and the switch needs to be replaced. Switches comes in many shapes and sizes but all can be tested with a continuity tester, which are available in analog and digital models.
Click on the video below for instructions on using a Continuity Tester to perform continuity test on switches.