Heater circuit part 2

I have a Whirlpool dishwasher with the clean light blinking seven times. The tests that have been performed to date are:

High limit thermostat resistance = 0.7 when cold

heating element resistance = 10.7

Thermistor resistance at around 78F = 49K

Checked White-violet wire from heating element to switch - 0.7

Checked switch - when open - infinite, when closed - 0.7

white violet at switch to white red at board - 10.7

reset and ran with jumper across white and white violet at switch - still had error

replaced circuit board. Reset and ran. blinking light returns

Any help would be appreciated. Only thing I can think of is that the high limit thermostat is not opening when it gets how (the cycle freezes for a while at 60 something minutes remaining and the dishes don’t seem to get wet) There is water in the tub when I open it while it is frozen, and the heating element is hot (I made the mistake of touching it).

Original thread: http://forum.appliancepartspros.com/dishwasher-repair/23296-heater-circuit.html

Just a couple thoughts. The thermostat is a safety components and should only open if the heater goes haywire opening the circuit and preventing damage. So if it is reading as a closed circuit, it is fine. Do you hear the pump operating and actually pumping water. You mentioned the dishes don’t seem to get wet. If the pump is not circulating water, it will never contact the element and thus never heat. Not heating will result in the clean light error.

I don’t think it is pumping water. I can hear a buzz which may be it trying to pump it but I’m not sure. Is there a way to test the pump? Should I open the pump up and see if there are any damaged parts?

That buzz is probably the motor trying to run. It could be a wire off the capacitor not allowing it to start, or something is stuck in the pump preventing it from starting. Time to open it up and see what is amiss.

Looking at the diagram, it seems that the pump assembly can be opened up from above, or the motor for it can be taken apart from below. Am I correct that I should start at the bottom and move up since the motor seems to be the issue?

Start at the top because with the top removed, you can get to the chopper and the end of the motor and see if it will spin by hand.

I am able to turn the chopper assembly about 3/4 of a turn, the it gets stuck.

You must have something stuck in the impeller. It is located behind the chopper and you can get to it by sticking your finger in the opening above the chopper. Try moving it back and fourth to see if you can free it up. If not, the sump will need to be pulled so you can separate the motor from the sump and find what is causing the problem.

I can move it back and fourth and free it up, but it just jams again. I reached in to the opening but I was unable to get anything out. Seems I am going to spend tomorrow evening taking the sump out. Do I remove it from above or below? I would think from below but I’m not sure how it comes out from looking at the diagram.

Remove it from above. I wrote a post Replacing Kitchenaid and Whirlpool Tall Tub Dishwasher Pumps on my blog about removing this sump assembly. See if that helps.

I started to remove the motor and noticed that the motor shaft where it leads to the chopper is rusted and doesn’t’ turn. I opened up the motor and the bearing closer to the chopper is rusted and broken apart. Do I need a new motor, or can I repair this one somehow?

Just order a new motor ([COLOR=#0066cc]AP3179651[/COLOR]) and mount it to the sump you already have. The new motor goes on easy and then you will have a working dishwasher again.

The pump is replaced and we ran it. Success. Thank you for your help.

Congrats
You have put a lot of time and effort into this
I am very happy to see you are up and running

denman