VERY Unique troubleshooting issue. No one has yet to provide a solution

FrakeTrain

Premium Member
Joined
Apr 15, 2019
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8
Location
Colorado
Hello. I've attempted all troubleshooting techniques that I am capable. Please make any suggestions you may have. No other forums have provided any viable suggestions...

Dryer: Maytag MDE2400AYW

Problem: Dryer producing very little heat.
Assumptions: Problem with Resetable Thermal fuse (sensor), High Limit Thermostat (sensor), Thermistor (sensor), or Heating element.

Troubleshooting steps:
Took top off unit so I could see the element condition while running. Turned unit on and I could feel low heat, but the element was not glowing red. I then removed the element from the unit and placed on the floor and connected back to harness. Turned on unit and element glowed full red. I then checked for continuity, resistance, and ground short (element housing continuity with element). All looked ok. So then moved on to other items.

Placed element back in unit. I then removed both the Resetable Thermal fuse and High Limit Thermostat from the back of the element housing cover (but kept the wires connected) and placed off to the side. Turned unit on, same low heat issue. Then I pulled the wires from both of these 'sensors' and hard wired the harnesses together to completely remove them from the schematic (totally closed circuit). Turned unit on, same issue. Checked both sensors for continuity, both ok.

Ok, got to be the Thermistor. I then removed the Thermistor from the fan duct. Kept the wires connected, pulled Thermistor outside unit, placed inside towel to isolate from any temperature changes. Turned unit on, SAME ISSUE. So not a sensor problem. I checked the Thermistor resistance at 68 degrees and matched exactly the service manual (60K Ohm) and then changed ambient temperature while testing resistance and thermistor reacted accordingly.

Ok here's the kicker...
Now, the element is installed, the two thermostats (sensors) are disconnected and their harnesses hard-wired together, and the thermistor is connected but outside the unit inside a towel. I then remove the lint filter, check for any obstructions in the blower and tape the door switch closed. I open the door to 90 degrees. I turn the unit on... and WHOA, full red glow form the element. I then start closing the door and when it gets to about 1" from shutting, the element starts to decrease in glow, At door fully closed, the element goes back to no red glow, but producing low heat. WTF!!! I have removed all the sensors from the electrical equation and element is still reacting to something.

Now, time to take out the service manual and check for codes and resistances through the board. No codes show up, and all the diagnostic steps and resistance tests through the board show anything wrong. I even tested the voltage across the element while the door was moving to turn the element from red to low heat and the voltage remained at 240V.

Is it possible that air blowing past a "weak" element is causing it to cool off? Or is there some other sensor that I am missing and is not on the schematic that is reacting when outside air starts to be pulled through the element and then warm air from the glowing element through the unit blower. The blower seems to be working perfect and the drum is turning as always.

I have attached the last page of the service manual for the Schematic.

Please any suggestions are worth trying at this point. The dryer is pretty old and the element is one of those self contained pricey units (over $100) so not worth replacing to troubleshoot.

Thanks in advance
 

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