How to Troubleshoot a Dishwasher
- 1). Is your dishwasher working at all? try different functions to see what is working and what is not working. If nothing works the first thing we must do is test for voltage to the unit. Remove the bottom access panel on the unit. This is usually done by removing two to 4 1/4 hex head screw depending on the manufacturer. Carefully remove the panel to expose the underside of the dish washer. use EXSTREAM caution!!! There are a few exposed wire leads that is touched will cause electrical shock. Now Usually on the right hand side there is a place where your supply voltage wire comes into the unit, it usually has another 1/4 inch hex screw securing a "cap" over the connection. Use a non-contact voltage meter if you have one to determine if there is voltage present. The wires here are usually caped together with a wire nut. If you find voltage here, inspect the wire nuts to see if wires are secure, Some times these wire become loose and will not make a good connection, if wires are secure then go to next step, if wires were not secure, turn power to unit off at breaker and retest with meter to determine that power is turned off to unit. Re-secure wires in wire nut firmly turn breaker on and retest unit to see if it now works.
- 2). If the machines motor works but will not fill this could be either the fill valve or the float switch. The float switch is usually on the left hand side of the unit. The float inside the unit rises and a pin connected to the unit then lefts up and a micro switch is then deactivated causing the voltage to the water valve to stop. Turn the power off to the unit at the breaker, then using your ohm meter check for continuity across the micro switch on the float switch. test it with the float down and you should read continuity, with the switch up you should read infinity or no continuity, if your meter has a buzzer to check continuity use the buzzer function. If you have good continuity the switch is okay, if not replace the switch. now check continuity ti the water valve itself, remove the leads to the valve and check congruity as you did the switch. If continuity checks OK restore power to the unit and check to see if voltage is present at fill valve. If voltage is present then replace the water valve, the solenoid is week and not opening.
- 3). If you have no voltage to water valve and no voltage present to float switch yet the motor will work, again turn power off to unit at breaker, now remove the inner door panel to the washer to access the control area. The water valve wires are usually blue, but check the colors of the wires on your unit, then trace the wires to the control board or control timer. Restore power to unit and check for power at the board or timer, if non is present replace timer or board.
- 4). If you have power at the junction where the unit is supplied with power and nothing at all works, turn power off to the unit at the breaker. Remove inner panel to washer to expose the control area. For Whirlpool and Kitchen-Aide washers, look for a white plastic clip with two wires that is clipped to the control board, remove the wires and using your ohm meter check to see if the circuit is open or closed, if the ohm reading shows continuity, then thermal fuse is okay, if no continuity is shown replace fuse. If continuity is good now check the micro switches on the door switches, see if they are good, they are marked normally open and normally closed, make sure switches are good, if they do not check OK replace switches. If switches are okay on all manufacturers then keep control section open, restore power to unit. Now with volt meter find the power coming in, it is usually black, You will need something to place in the latch of the door to simulate the door is closed, this will close the door switches. If you have power to the board, or to the timer and no power coming from the timer or control board replace timer or board. An easy way to make sure the door switches close is to remove the latch from the unit and place it into the latch cradle, and it would be as if the door was closed.
- 5). If you have voltage to your timer or board, and you have voltage output to all your components then you have to determine if that voltage leaving the board is getting to the components. If they do not reach the components, i.e. the water valve or the motor, you have an open wire and the wire harness needs to be replaced. If you have voltage to the motor and motor does not run replace the motor. Note some motor have a start relay, this is found on the right hand side, It would be cheaper to start here if motor has voltage and does not run. Replace motor start relay first. then the motor if needed.
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