Testing a bi-metal switch
|Disconnect the power source to your dishwasher 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 can begin to test your dishwasher's bi-metal switch, you must first locate the device. It is located within the door assembly, in very close proximity to the detergent dispenser cup. You will need to gain access to the inside of the door.
Examine the outside of the appliance. Depending on the model, you will have to remove either the entire internal door panel, or the entire external door panel. In each case, the panel can be removed by removing anywhere from 6 - 10 screws. Be careful to not remove the screws at the very bottom of the door that are actually a part of the hinge assembly. Removing the hinge assembly screws will remove the entire door from the appliance, which is not at all necessary to test the unit's bi-metal switch. With all of the screws removed, the door panel should be easy to lift off of the door assembly. If you have difficulty lifting the panel, look for additional screws you may have missed.
With the door panel removed, locate your dishwasher's detergent dispenser cup and the bi-metal switch assembly. Before you begin to test the switch, you should first check its alignment. If the detergent cup door is open, shut it. Use a small screwdriver to gently push in on the metal until the door of the detergent cup opens. It might just be that the switch has fallen out of alignment. Sometimes, only a slight adjustment is needed to allow the switch to open the detergent cup door. If this is not the case with your dishwasher, continue with the test.
There are two wires connected to the bi-metal switch. Label them so that you will be able to correctly reconnect them later. Remove each of the two wires from their respective terminals - they are connected with slip-on connectors. When removing the wires, grasp the connectors and pull firmly. Do not pull on the wires themselves. You may want to use a pair of needle-nosed pliers to help you.
Now test for continuity using your multimeter. Set it to the x 1 ohms setting. Take each of the meter's probes and touch them to one terminal each. If you receive a reading of infinity, you should replace the switch.