Shut off the dishwasher's power source in your main breaker panel.
Open the dishwasher door, then remove the screws securing the control panel to the door.
Close the dishwasher door, but do not latch it.
Rotate the control panel down, then disconnect the ribbon wire from the control board. Disconnect the rinse aid sensor wire, if applicable to your model. Place the control panel in a secure location.
Locate the thermal fuse, which is clipped to the side of the control board.
Pull the two wire connectors off the terminals on the thermal fuse.
Set the multimeter to the lowest setting that can be used to measure resistance in ohms, then calibrate the meter. For instructions specific to your meter, refer to the owner's manual.
Touch one of the terminals on the fuse with one of the multimeter's probes. Touch the other terminal with the other probe.
Look at the resistance reading on the multimeter's display. If the meter indicates a resistance between 0 and 50 ohms, then the fuse is functioning properly. If the meter displays any other resistance, you must replace the fuse.