How to test a dryer's door switch:



Common dryer door switch Testing a door switch

Note:
Disconnect the power source to your dryer before you conduct this or any other test. Either unplug the unit from the wall outlet, remove the appropriate fuse from the fuse box, or flip the appropriate breaker in the circuit breaker panel.

Before you test the door switch, examine the prong that comes into contact with the switch when the door closes. If this prong is broken or damaged in any way, then your door switch may be just fine. The prong may be the reason the door switch is not engaging.

A door switch is a simple on/off mechanism that prohibits the dryer from operating when the door is open. Dryer door switches are a little over an inch long. Many are white in color and all have metal prongs, called terminals, extending out from the body of the switch.

Some door switches have only two metal prongs extending from the body, while others have three. Those with three terminals will have a common (COM) terminal, a normally closed (N.C.) terminal, and a normally open (N.O.) terminal. Those switches with only two terminals will have either a common terminal and a normally open terminal, or a common terminal and a normally closed terminal. We are providing directions for testing a door switch with three terminals. If you are dealing with a door switch that has only two terminals, ignore the part of this test that does not apply to you.

Locate your dryer's door switch. It will be located around the door opening in the front panel. You may be able to pop the switch out of place, or remove it by removing only a single screw. If you are unable to access your dryer's door switch this way, you will have to remove the front panel of your dryer. See our section How to open up your dryer for details.

Label each of the two wires leading to the door switch so that you will be able to correctly reattach them later. Using caution, remove the two wires. They are both connected with the use of metal slip-on connectors. Grasp the connectors and pull firmly from the connectors. Do not pull on the wires themselves. You may need to use a pair of needle nose pliers to help you.

Use your ohmmeter to test your switch for continuity. Begin by setting your ohmmeter to measure resistance at a scale of R x 1. If yours is a two-wire switch, touch each tester probe to each of the switch's terminals. You should receive a reading of infinity. While the probes are still touching the switch's terminals, press in on and hold the switch. The reading should change to zero.

If the test you conduct does not produce these results, you should replace the switch.