My old Dometic fridge acting up…..

[JFXG]

Need a consult, and thanks.
My ‘02 Dutch Star still has its OEM Dometic NDR1292 fridge. I had to put a Dino card in it about 6 years ago, and new AC heat elements and a thermistor about 4 years ago. For the last 4+ years it has run stable with the freezer at +12* and the box in the green on my gauge at 33-38*.
This morning I found the box at about 30*. Checked the freezer at +5*. I had appointments scheduled, no time to fiddle with it, so I opened the door and let the cold spill out for a few minutes to control the temp. I keep remembering that the thermistor failure mode is to run wide open, so that’s what crosses my mind. I’ve set the control from #5 down to #3, but so far that doesn’t seem to have had any great effect. There have been no other signs of trouble… no icing, melting, smells, etc.
I will poke at it more tomorrow, but do any of you appliance experts (O-B?) think of anything more obvious than the thermistor?
Thanks!!

[Old-Biscuit]

Correct
Thermistor Failure mode is for fridge to run continuously ​either due to bad thermistor or thermistor that has fallen out of clip and is hanging down

IF bad replace thermistor
Snip-The-Tip Replacement is good option....rheostat that connects to thermistor wiring vs trying to run new leads down to circuit board

https://www.snip-the-tip.com/cgi-bin/articca.cgi

[JFXG]

Originally Posted by Old-Biscuit

Correct
Thermistor Failure mode is for fridge to run continuously ​either due to bad thermistor or thermistor that has fallen out of clip and is hanging down

IF bad replace thermistor
Snip-The-Tip Replacement is good option....rheostat that connects to thermistor wiring vs trying to run new leads down to circuit board

https://www.snip-the-tip.com/cgi-bin/articca.cgi

Thanks, OB. I have a couple of RV supplies nearby, can act on it quickly.
Now, please refresh me on thermistor adjustment! My thermistor is mounted on the fourth fin from the right (as I face the fridge). Is this a proper location? And movement… sliding thermistor up lowers box temp? I should write this down…. [emoji43]*[emoji94]

[Old-Biscuit]

OEM thermistor S/B on far right FIN mid position

Thermostat is factory calibrated for temp range (34*F - 42*F) based on that location
*Moving the thermistor UP/Colder or DOWN/Warmer is for those fridge models that use an Automatic Temp Control (No adjustable temp settings)

Snip-The-Tip is a rheostat control that mounts to side wall,
Cut the OEM thermistor off and splice the rheostat wires on (all in the kit)
Then use the OEM Temp settings on Upper panel and the Rheostat as a fine tuner (6*F - 8*F) affect

Dinosaur Electronics has a thermistor adjustor....goes between Thermistor leads and circuit board connection. It is also a rheostat/fine tuner But OEM thermistor must be good/working

[JFXG]

OK. Sorry I’ve been slow to confirm. I installed a new thermistor several days ago, and I’ve returned to my normal ops- freezer ~12*, box in the lower green, ~33*-35*.
As before, I have to use temp setting #5 to achieve this range. I would like to bring this down a step, hopefully to get the freezer to 0* or below. I think the problem lies with the door gaskets, particularly the freezer. My freezer frosts up rapidly, requiring a defrost about every 3 months. I’ve found the proper gasket set on EBay for $185+, but I hesitate to put this amount into a machine that could die tomorrow with no regrets.
Has anyone replaced their door gaskets and achieved substantial improvement? Thanks!

[Old-Biscuit]

Before replacing seals with some kit (Dometic doesn't offer replacement seals) try to RESET your OEM Seals

Thoroughly clean the seals....soapy water/good rinse/wipe dry
All surfaces of seals and door frame
Take some cottonballs and place them under the seals in each corner
Then using Hair Dryers.....warm the entire seal
(2 people/2 dryers)
Warm all the way around....NOT HOT but warm to the touch entire seal
Once fully warmed...close door/fridge running ---leave door closed for hour or so until seals have fully cooled
Remove cottonballs and the 'dollar bill' test door seals in several areas
*Place bill between seal/fridge frame...close door the pull bill out
S/B Strong resistance

If seals do not reset then go ahead with planned seal replacement kit
*Freezer frosting up routinely/frequently will NEVER allow cooler temps to be achieved

[JFXG]

Thanks, OB. One question- could you please clarify step 3 of your instruction?
“….Take some cottonballs and place them under the seals in each corner….”
Do I separate the seal from the frame and tuck the cot balls under? I’m unable to form a mental picture…..
Thanks!