refrigerator temp display wrong

[richiebklyn]

My refrigerator temperature display reading is incorrect and always changing. After I take the refrigerator plug out and back in, it is at the correct set 35 degrees. After 20 minutes it goes to OP and then -20s and starts to make its way back to 35 degrees over time, but it jumps to a different temp some time after. It seems like when I have foil items in the fridge it is worse, temp changing to negative numbers more frequently and more often.

My freezer temp display is correct, 0 on the display and similar temp inside as read on a hand thermometer. The inside temp of my fridge is between 37-45 as read with a hand thermometer. So its cold but not at the set 35 degrees. (top shelf 45ish lower shelves high 30s)

At this time I have replaced the refrigerator side thermistor, performed a diagnostic a few times after removing the plug from the wall and plugging back in. All parts seem to be working from what I can tell after scrolling through the diagnostic tests.

I took all plugs out of electronic control board and put them back in as well. Anything else I should do before I purchase a new electronic control board? Thank you for your time.

Rich

[evaappliance]

Need to post your model number so someone can help you. Every brand has it’s unique causes to issues 

[richiebklyn]

FGHC2331PFAA thanks

[isaac]

Based on you complain Seems like one of your fridge thermistors is failing

[richiebklyn]

I changed the thermistor on the refrigerator back wall about 2 weeks ago.  Does the refrigerator side have another one?  I did not find it in the parts list on the frigidaire website.

[isaac]

1 hour ago, richiebklyn said:

Does the refrigerator side have another one?

the wiring diagram shows 2 in fridge compartment, didnt see it on the breakdown but it will be the same part number, just try to look for it around the bottom half, keep us updated

[evaappliance]

I’m wondering if one is in the damper control and you have to purchase the damper assembly?????    Maybe ???    

[isaac]

3 hours ago, evaappliance said:

I’m wondering if one is in the damper control and you have to purchase the damper assembly?????    Maybe ???    

Don't think so on this model but i guess anything is possible,  if he can get us some pictures of the unit inside might help us out

[richiebklyn]

Thanks for your help gents!  I can not find a 2nd piece that looks like the first thermistor I changed inside the fridge.

These are the pics of the inside of the fridge.

https://www.repairclinic.com/ProductDetail/1933337?tab=diagrams#

 

I have some more info for you as well.   In the last 12 hours the fridge display reads 14 and the damper does not open to cool the fridge, maybe because the reading stays below 35 degrees and the fridge thinks its cold enough inside?

I shut off the fridge for over an hour to see if something might be frozen to keep the display in the teens but when I turned the fridge back on it came back to 14 degrees in the frig temp display. If this was a thermistor problem would I expect to see a higher reading considering the refrigerator was off and the temp had time to rise?

I did another diagnostic, air damper worked during test. Test #29 ff thermistor, showed a constantly changing temp every few seconds, 14 ,8, -22, etc.

How can I find out what is causing the ff thermistor changes in the diagnostic test? I don't want to buy another damper and electronic board to find out the problem is a hidden second thermistor as you may suspect. Thanks for your time.

 

This might sound crazy but I removed a pot with food in it and temp display went back to the set 35.  Pots and aluminum trays makes this temp reading worse.
 

[isaac]

Without seeing the actual unit i cant say for sure that there's a second sensor but the electrical  diagram shows very clear 2 fridge sensors, however in the 2nd diagram i found that only in led models there's a second sensor,  why dont you go to the control and messure the reading of the sensors from the main control,  looking at the board will confirm if there's anothr sensor or not, fridge at 37F should read about 28K (to be exact 28,300 ohm) 

Keep us updated on the progress 

[richiebklyn]

Thank you Isaac.  Please look at the link I posted above, it is the diagram of my refrigerator.  It shows the inside of the unit.  I have spent the morning trying to contact frigidaire about the 2nd thermistor in the fridge, but I have been unsuccessul finding someone who can answer that question.

     I do not know how to measure readings from the sensors, but thanks for suggesting.

     

[isaac]

8 hours ago, richiebklyn said:

I have spent the morning trying to contact frigidaire about the 2nd thermistor in the fridge, but I have been unsuccessul finding someone who can answer that question.

Is your model with led lights?  Or regular bulbs? Based on the diagram it seemes like your is regular bulbs which means only 1 thermistor in fridge,  if that the case you will need to measure the resistance of the sensor from the board otherwise you dont know if there's a bad wire or sensors,  or possibly a bad biard reading it wrong,  without that readings we will be doing to much guessing 

[richiebklyn]

I do not have led lights.  I have regular bulbs.  

I do not know how to measure resistance or have such tools. 

[richiebklyn]

I had an electrician friend come over today and read the resistance of the thermistor and wires.

This is the procedure we found and did:

OP in refrigerator temperature display

Refrigerator temperature sensor open

Check/Repair

Unplug the refrigerator and check wiring connections between the refrigerator temperature sensor and the electronic control board. Reconnect any loose wires. If wiring is okay, unplug the refrigerator temperature sensor from its wire harness and measure the resistance of the sensor using a multimeter. The meter should measure 28,300 ohms if the sensor temperature is 37 degrees, 32,566 ohms at 32 degrees and 11,304 ohms at 72 degrees (room temperature). Replace the sensor if the meter measures infinite resistance. If the meter measures correct resistance through the sensor, plug the temperature sensor back in and measure resistance through the refrigerator temperature sensor wires that connect to the electronic control board (the gray/black wires on the J4A connector). Unplug the J4A connector from the control board and measure resistance through the gray/black wires. The meter should read the same resistance as for the temperature sensor. If the meter measures correct sensor resistance through the wires, you'll likely need to replace the electronic control board because it's not accurately detecting sensor resistance. Find and repair the sensor wiring failure if the meter measures infinite resistance through the sensor wires.

 

  At the time the fridge was about 50 degrees and the thermistor read 18.200  We took the thermistor out and let it sit at room temp for a while and it read 10.900.  That seems ok from what I read above.

     When he plugged the thermistor back in and unplugged the wires at the board, as explained in the directions, j4a connector from the control board and measure resistance through gray/black wires.  The meter read infinite resistance.  That seems like the problem.

Do you think this is a sensor wire failure?

 How do I find and repair the sensor wiring failure since the meter measured infinite resistance through the wires? 

 

Thanks,

 

Rich

[Vance R]

Look over the connector for corrosion, wires for nicks or kinks.  To find out which wire is open requires long meter leads and usually 2 people, just ohm out each wire individually.  Once you figuire out which wire is open lightly tug on the wire near the connector. Sometimes they over crimp the connector and it cuts the wire.  If can't find any visible issue try using a straight pin to pierce the insulation to ohm out the wire - note this a last ditch effort to find the broken spot. If you suspect the broken spot is in the liner splice and run a jumper through any hole to make the repair.

[richiebklyn]

  I did not find any corrosion in or on the connectors.  I did not find any nicks or kinks in the wires.  I did not find any visible issue.   I do not know how to perform the rest of the tasks.  

Do you think a refrigerator tech can fix this problem or am I continuing to throw away money?  

 

Thanks,

Rich

[Vance R]

3 hours ago, richiebklyn said:

Do you think a refrigerator tech can fix this problem or am I continuing to throw away money?  

That depends on the experience level of the tech. 

[Ashton]

Make sure the evaporator fan spins, check it, don’t assume.