There's no heat in my dishwasher. It's most likely the heating element as I found a plastic cover melted on it. I tried to measure the resistance but it was like zero. Before I can confirm I broke it.
So I ordered a new one, put it in, and then nothing happened. I measured the resistance of the new one. It was definitely zero. I asked the seller and he said I can get a replacement or refund. I opted for replacement. I measured the voltage at the control box and it was nothing. So I ordered a new control box too.
Before I rant more, the correct way is simple but not found in a web search. First, locate the service manual hidden somewhere in the kick plate. You may not need it if you are lucky but otherwise, you have to buy it online. Is that even legal? To sell Whirlpool's manual when Whirlpool provided for free but not online.
You don't need to take out the heating element to test it. Just unplug it at the bottom near the rear. You also don't need to flip the back of the dishwasher on it's back, lying flat on the ground. This model can rest at an inclined angle so you can get to the heating element from down under. Pull out the connector and you can see the terminals. The resistance should be a little more than 10 ohms.
If the resistance is 10 ohm, the current is 120/10=12 A. Normally the current rating is 15A max so your model could have a little less resistance. For 20 ohm the current is 6A, which is too small unless it's very energy efficient.
If your ohmmeter is old or you are not sure about the battery charge, you should test it with a small value resistor like 10 ohms. All my trouble started because my old analog cannot measure small resistance, while all other measurements are functional. So I was wrong about faulty elements; it was my meter.
You don't need a meter for testing the element. It's highly not recommended to pass 120V across the element terminals. The control board actually does this via relay switches. If you want to do this, you have to use wires, connectors, plugs, and sockets rated for 15A, or you fuse will blow or your circuit breaker trips. That's my second mistake. I thought the element actually has almost zero resistance but what burned my plug and tripped the circuit breaker was the excess current on my insufficient rated circuit elements.
It's true that you have to "reset" the dishwasher before it works again. Actually, you need to clear the error codes stored in the machine. Power off reset doesn't do it. Pick any three buttons 1,2,3. Press them in the sequence 1,2,3,1,2,3,1,2,3 with 1 sec max between each button. Then the diagnostic routine will start. I don't think the fault codes will be automatically cleared when the routine finishes. Maybe it does. Whatever, you need to put in a working element so the diagnostic routine will pass and the fault may be cleared.
What happened is that in normal operation or in diagnosis, if a fault is detected, the power to that component, typically the heating element or the motors, is cut off for safety. The cut off will not be reversed unless you run a diagnostic routine.
On the first part of the routine, the machine displays up to 3 2-part error codes by blinking on the clean LED alone! Each code is separated by 5 sec of pause. There is a 2 sec pause in the 2-part code. So if the clean LED blinks 7 times, pause 2 sec and then blink once, you have an error code of 7-1. You can look up the Sears parts website but I never know what it is before I discovered the service manual.
After the error codes, you press the HI Temp button (or is it the Dry button?) to clear the fault codes. Then that button will blink twice to confirm. If there's no confirmation you have to open and close the door. So you can just run the diagnostic routine again to see if there are still any fault codes and that the button blinks twice.
So actually I'm doing everything for nothing. My original heating element may even be working before I broke it. I just need to clear the fault codes, like resetting the circuit breaker. Simple as that! I ended up buying a replacement, a replacement of the replacement, and another from I think a more reliable source that is more expensive and cost over $11 to ship. But that's not too bad. The first seller just agrees with me that all the elements are faulty and refunded me instead of giving me free repair advice. The 2nd seller has a good refund policy but I lost shipping both ways.
More, I bought a new control box but my old one could still be working. I just need to run diagnostics to clear the fault. So it's pointless to run the dishwasher normally to measure the voltage across the heating element without connecting it. Even if you can get the voltage you won't get it on the next run because the dishwasher will take it as a fault and cut off the power to it.
But that's not too bad. The box may be less expensive than a service call. I can even return it but I don't bother to open the door up and replace the new one with old one.
If running the diagnostic routine doesn't reset the machine, there's little you can do without the service manual. The fuses are at the back of the circuit board. You can test things on it, like fuses and the thermister, only if you know the terminal or connector number. And you don't need to go down to access the bottom of the machine because the test points are all on the circuit board.
Opening up the door isn't that difficult. You need a T15 torx screw bit for the door and a T8 bit for the control box. Opening up the control box is a bit tricky without the service manual but doable. But there's no point to open it when you don't have the manual.
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