Testing a dishwasher timer
|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 flick the appropriate breaker in the circuit breaker panel.|
The purpose of a dishwasher timer is to control the unit's cycles by regulating the length of time that power is directed to each component. It is not common for dishwasher timers to malfunction, and they are often misdiagnosed as having failed when they are actually fully operational.
TIP: If you do have a timer motor that has failed, consider replacing just the motor itself and not the entire assembly. Timer motors can be considerably cheaper than the complete timer assembly.
Before you can begin to test your dishwasher's timer motor, you must first locate the device. It is a part of the timer assembly. Timer assemblies are located either in the control panel at the top of the dishwasher door, or behind the lower kickplate at the bottom of the unit.
To get to a timer located in the unit's control panel, first examine the outside of the appliance. Sometimes, depending on the model, you only have to remove a couple of screws in order to remove the outer control panel. In other cases, 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 timer. 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 other screws you may have missed. There may or may not be a smaller control panel cover. If you do discover one, it will be held in place with either a couple of screws or a couple of clips.
With the dishwasher's control components fully exposed, you may discover that your model uses two timer motors. The second one will be a rapid advance motor. It is operational when the wash cycle is cancelled or reset. If you are unsure which timer is which, then test each of them.
To get to a dishwasher timer located behind the lower kickplate at the bottom of the unit, simply remove the few screws holding the kickplate panel in place. With the panel removed, you will be able to identify and locate the timer and its motor.
There will be two wires extending from the round motor housing. Follow the wires until you locate the connectors. Label the wires so that you will be able to reconnect them later in the right positions. Carefuly remove the wires. Do not pull on the wire itself. Needle nose pliers may be needed to pull gently on the wire connector.
Set your ohmmeter to the x 1000 setting. Take each probe and touch it to one wire. A normal reading for most dishwashers is in the 2000 to 3500 ohms range. Try to locate a schematic for your dishwasher. It should be in one of the service areas of your dishwasher or in the owner's manual. This schematic should indicate the proper resistance reading for your specific timer motor.
If the reading you receive from testing your timer's motor differs greatly from the range presented here, then you should replace your timer motor, or the entire timer assembly.