Test a 4 way switch turn off power to the switches at the circuit breaker and using a tester make sure power is off. Remove the screws on the switch cover plate and pull off the cover plate to expose the switch wiring.
Understanding Three Way Wall Switches
How to test a 4 way switch. A is a 3 way b is a 4 way and c is a 3 way turn knob dimmer. When connected properly a simple flip of any of the switches will turn on the light. As long as switch a is in the up position the other two function as expected. But when switch a is down the light will not turn on at all from either of the other points. If the device is still. The four way switch is not used on its own but in addition to a combination of switches.
Place the other lead on any other terminal except the green ground terminal. If the device is a switch the tester should go off and on when you flip the switch. Place a at the 4 way box and send b with the meter to the 3 way box. Turn on the light or device being controlled by the 3 way switches if you already have them. Using a continuity tester on the 4 way switches check continuity between one of. Turn off electric power.
Put the switch into the on position. A three way switch connects travelers from that switch to one side of the four way switch while the other side is connected to the other three way switch and the three way switch is then connected to a light. Remove all of the. Follow the how to troubleshoot 3 way switches link to test the 3 way switches. Without touching any wires test each wire in the electrical box with a non contact voltage tester. Return to location you plan to wire to verify that there is no electric flow to that device.
To test a 4 way switch connect one probe to one traveler terminal in a pair and the other probe to one traveler terminal in the other pair. This video shows how to test and replace a 3 way switch along with some wiring basics. Connect the red lead to one of the terminals on the switch. Also test each of the side terminals on the switch. If the tester lights up beeps or shows 0 resistance it means that electricity can flow freely between those terminals and in most cases that means that the device is good. Connect the black lead to the other terminal on the switch.
Move one probe to the other terminal in its pair and test again for the same results. Flip the switch toggle and check that you find continuity in one direction but not the other. The meter should display 1 ohm or less meaning the switch is on. Starting with safety and understanding 1. Have a tap the second pair of wires in the box together as b measures the resistance between pairs of wires in the 3 way box until the connecting pair is identified.