Maytag MRT519SZDH00 Warm Refrigator

RobF

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Model Number
MRT519SZDH00
Brand
Maytag
Age
1-5 years
I have a Maytag Refrigerator MRT519SZDH00, the refrigerator is running at 50°F the freezer is running at 10°

I replace the freezer thermistor last June. I also replaced the control-box last August to fix a cold freezer and a warm refrigerator. Recently I had ice build up that was causing leaks in the refrigerator and in the freezer. I solved that by a through defrosting and making sure the freezer drain is open.

A few days after defrosting the refrigerator is running at 50°F. I tried turning up the temperature setting to Max, to no effect.
 

Jake

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RobF

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Hi Jake,

I turned of the unit for 24 hours two weeks ago. I removed the back of the freezer and this is how it looks

DSCN7937.JPG

I will add another image once I can safely remove the Styrofoam piece, it is frozen in place now. I know there is ice on the fan, because I can hear it when the fan is running.
 

Jake

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Yes, its frosted up for sure.

You'll need to ohm test the defrost thermostat and defrost heater.

Here's the defrost thermistor for your model:
WPW10392132 Bimetl-Def


Oh wait, I just saw your other thread from last year and you already replaced the defrost thermostat?

But isn't the one you replaced the evaporator thermistor here:
WPW10383615 Thermistor


Did you see the defrost thermostat, the larger black one, I just posted above? Can you please read me the temperature rating that's stamped on it?

Here's the defrost heater for your model:
WPW10316428 Heater


Jake
 

RobF

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How do I do that? There is no information in the service and wiring sheet. Can you tell me where I can locate the Bimetl-Def? I looked in the back of the freezer, nothing there that looks like the picture in the item description. I checked in the refrigerator area, only thing there is the cooling tower and the control box. The cooling tower has a sensor, but it doesn't look like the picture.



Correct this was my first replacement for the unit.
 

Jake

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The defrost thermostat should be clipped onto the top coil of your evaporator coil.

It comes from the main wire harness in the freezer.

Here's the parts diagram for your model: Parts for Maytag MRT519SZDH00: Liner Parts

#25 is the main wire harness

#20 is the defrost thermostat

Jake
 

RobF

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Jake,

I must be missing something or my unit does not have a Bimetl-Def. I'm looking for something the size of 4 dimes.

DSCN7939_1.jpg

I traced all the wires coming into the freezer, in the red circle. The only thing touching the evaporator coil is the evaporator thermistor, in the blue circle. I traced the other wires going to the plug for the ice maker & the fan.

Any help would be appreciated.
 

bigbuck

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At least that is what I think.Here is the parts list. Page 4 harness 25 ,but they do show bimetal number 20 that you don't have and leaves that black thing as a thermal fuse which looks like a ice maker thermal fuse as known to us.

Weird look up though. Check for continuity with meter.
 

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Jake

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Thanks bigbuck!

Yes Rob, I see what you mean.

Something is weird, because it shows the defrost thermostat in your parts diagram and it is the one that bigbuck circled, but it looks like a in-line thermal fuse rather than a defrost thermostat.

Jake
 

Jake

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I think I know now, if the in-line thermal fuse goes out, then want you do replace it with a regular defrost thermostat.:)

So Rob, ohm test that in-line fuse for continuity.

Jake
 

RobF

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Going to be as detailed as possible to make sure I'm not missing something stupid/obvious.

I set my multi-meter to continuity test. (Don't have much experience with a multi-meter)

DSCN7942.JPG

I disconnect the harness to test the fuse. I got continuity from the fuse.

Next I disconnected the defrost heater, but did not remove it. I got continuity from the heater.
 

Jake

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Your meter is not set correctly.

See the Ω ohm sign on your meter, that's ohms, set it on 200.

Jake
 

Jake

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Nevermind, its been a long day, its set properly, I was looking at the wrong side of your meter dial.

Your fuse is good then if it shows 0 ohms.

How many ohms from the defrost heater?

Jake
 

RobF

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Thanks Jake,

The fuse is indeed reading 000

The defrost heater is reading 036. Just for completeness I set my meter at 200, and it is reading 36.6.

Thanks for your help.
 

Jake

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Both are good then.

I'd ohm test the freezer evaporator thermistor now, WHILE ITS FROSTY, you should read 8.7K ohms. Unplug the refrigerator first before ohm testing.

But isn't the one you replaced the evaporator thermistor here:
WPW10383615 Thermistor


Jake
 

RobF

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Correct I replace this part last June.

I left my multimeter in the same position as in my previous post. I got reading of 1500, but it kept dropping. It seemed to stop around 500, but it did not stay steady at any one reading. As you mentioned I did not let the freezer warm up, the sensor has a nice amount of frost on it.

I also set the multimeter to 200 Ω, in that position it stayed at 1.

As a side note both the refrigerator and freezer are maintaining the correct temperature, but there is frost build up in the freezer.

Thank you for your patience in helping me diagnose this :)
 

Jake

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That's very strange, either your meter is acting up or that evaporator thermistor is bad.

Check your meter batteries, because WHILE ITS FROSTY, you should read 8.7K ohms.:)

Jake
 
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