KFIS29PBMS00 Evap fan issue - Refrigerator warm freezer normal

pete1

Premium Member
Joined
Mar 27, 2018
Messages
2
Location
Chicago
Model Number
KFIS29PBMS00
Brand
KitchenAid
Age
1-5 years
Hello,
I am having an issue with the fridge section. My freezer is working fine I have it set to 0F and it stays there. However the fridge portion is set to 36F and it stays between 50F - 60F. This model has a dual evaporator and I believe the evaporator fan for the refrigerator part is not working. The refrigerator evap coil freezes over and the fan never spins.

Ive tested the thermistor and the defrost thermistor and they are working fine. The resistance varies based on temp as specified in the tech sheet.

I have attached images of the motor location and a close up of the motor in question.
20180317_230047_resized.jpg
20180317_192019_resized.jpg

Here is a section of the tech sheet that came with the fridge:
schem.jpg

During the service test procedure it says I should be getting 14Volts from PWM (yellow) to GND (RD). That is what I get. Also when the fridge is running this voltage can drop down to 9V. I am assuming this is to change speed of fan.
As you can see from the image there is also a VCC(TN/OR). On VCC to ground I am always getting 0V.

My question is what is VCC supposed to be? Why am I always getting 0?

The same VCC connects to the Freezer fan and that one works fine.

So I ordered a new fan and same issue. The fan will not spin but the 14V is there.

Not sure what to try next. Do I keep buying fans until I get one that works?
 

jeff1

Appliance Tech - Moderator
Staff member
Joined
Oct 10, 2004
Messages
23,614
Location
Ontario, Canada
Hi,

So I ordered a new fan and same issue. The fan will not spin but the 14V is there.
Just a guess!!!! We would see similier issues with some boards where we test with a meter and it shows power but none is really there as indicated when we hook up the fan and ask for real power to run the fan and none is there and the fan motor does not run. I'd be inclined to try another board.

Control-Board-W10878993-02015140.jpg Control Board Service kit. This kit contains both the high voltage control board and user interface. Both parts must be replaced together.

The refrigerator evap coil freezes over
If you have defrosting issues, I'd also do the sensors...

Wire-Harness-WPW10277799-02010954.jpg Refrigerator evaporator wire harness with temperature sensor

jeff.
 

rickgburton

Appliance Tech - Moderator
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Jul 11, 2006
Messages
33,484
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pete1

Premium Member
Joined
Mar 27, 2018
Messages
2
Location
Chicago
Well, after further investigation it turns out that the fan works.
The VCC wire (TN) should be 14V. I am not getting 14V on it.

If I put 14V on this wire and hook up the fan GND(Red) to ground and the PWM(yellow) to anything between 5V - 14V... the fan turns and the speed is controlled by the PWM voltage.

So the problem is I am not getting 14V on the VCC(tan) wire. I am getting 0.
I will investigate further to see if the wire is cut somewhere or the main board is not supplying the 14V to it.
 

ccichy

Member
Joined
Jun 9, 2019
Messages
2
Location
Wisconsin
Curious what the fix was, as I'm struggling with the same. Also, what's the secret to removing that cover to the fridge evap? Thanks folks. Great description here!
 

rickgburton

Appliance Tech - Moderator
Staff member
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Jul 11, 2006
Messages
33,484
Location
Murray, Utah 84107, United States
The fix is in the post before yours. Remove the Air Tower. Release 6 locking tabs, there are 2 tabs at 3 locations along the center shelf rail. Remove the 2 screws in the cover.
 

ccichy

Member
Joined
Jun 9, 2019
Messages
2
Location
Wisconsin
The fix is in the post before yours. Remove the Air Tower. Release 6 locking tabs, there are 2 tabs at 3 locations along the center shelf rail. Remove the 2 screws in the cover.
Thank you sir. I’ll take a look. Appreciate the help. Control board kit ordered (assuming this was the fix)
 

rickgburton

Appliance Tech - Moderator
Staff member
Joined
Jul 11, 2006
Messages
33,484
Location
Murray, Utah 84107, United States
For their problem it should have been. You're welcome to start a new thread and start from the beginning if you like.
 
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