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Dometic optional Thermistor Adjuster reduces refrigerator temperatu

Yahoo Message Number: 6017
While reading the technical service manual (available from Dometic), I noted that Dometic designs their refrigerators to cool to a nominal 43 degrees in the food storage box (with a designed operational range of 46 to 35 degrees plus or minus 3 degrees). I also noted that they make a Thermistor Adjuster that reduces the nominal cooling temperature by 3 degrees to 40 degrees. The part is about $12 and is available at many RV supply stores and www.dtiparts.com. The part number is 2932164011. It is a simple resistor plug that installs in- line with the thermistor wire at the back of the refrigerator.

We also have read on other web sites about folks installing an optional cooling fan in the back of the refrigerator to use on hot days. We noted that on hot days when we would turn the coolness number up to 3 or higher, we would get an accumulation of ice on the cooling vanes in the food storage box. So, I figured if I had better air circulation in the food storage box, I could eliminate the ice formation and get better cooling of the entire food storage box. So we added a 12v fan inside the food storage box too. Wow does it do a fantastic job at keeping the food storage box nice and cool even on the hottest days. We bought our 12v fans at Radio Shack. The big one (part number 273-238) pushes 85 cfm (cubic feet per minute) up the back of the refrigerator and greatly aids in cooling especially on hot days. The smaller one (part number 273-243) circulates 27 CFM around the food storage box and has completely eliminated ice formation on the interior vanes. The fans are brushless and have a tiny current draw (0.32 amp and 0.16 amp respectively), so they can easily use the 12v power source at the back of the refrigerator without overloading the refrigerator fuse. A 0.5 amp in-line fuse easily protects the fan circuits.

Maybe these tips will help your refrigerator to stay cooler on those hot summer days.

Robert

Re: Dometic optional Thermistor Adjuster reduces refrigerator tempe

Reply #1 –
Yahoo Message Number: 6019
Great idea Robert, how did you access the 12V source internally for the fan and where did you place it? Tom

02 Allure 30780

Re: Dometic optional Thermistor Adjuster reduces refrigerator tempe

Reply #2 –
Yahoo Message Number: 6020
The fan inside the food storage box is exactly the right size to fit along side the cooling fins. I removed the 3" x 3.5" plastic filler plate that fills in the back right side corner and used two plastic wire tires to hold the fan in place. The fan is supported by the same supports that hold the plastic filler plate in place - a perfect custom fit. I also removed the filler plate immediately below the fan to allow for air circulation. Since the warmer air accumulates at the top of the refrigerator, I aimed the fan blowing downward.
This sets up a circular flow of air inside the refrigerator that extracts all the available coolness from the cooling vanes and keeps them from freezing. The fan blows the warmer air down the right rear corner of the refrigerator and across the vegetable storage bins and then the naturally warm air flows upward through the cooling vanes.

While experimenting with this new design, I temporarily ran the 12v wire starting from the outside rear of the refrigerator, down along side the 1/2" water line (used for the ice maker), then toward the front of the refrigerator above the drawers (held in place with a few dobs of silicone caulking), then up through a tiny hole in the corner of the right front (just under the hinge), then over the front lip and into the refrigerator. Some day, I'll find a safe place to drill a hole through the back of the refrigerator without poking a hole in any wires or refrigeration tubes, but for now, this is working just great. I used flat super-thin two strand 20 gauge wire and it slides easily under the refrigerator seal without affecting the door closing or sealing. Since the interior fan only draws a tiny amount of electrical current, the super-thin wire does just fine.

I hope that answers your questions Tom.

Robert

Quote from: truk4u2003

Re: Dometic optional Thermistor Adjuster reduces refrigerator tempe

Reply #3 –
Yahoo Message Number: 6028
Your info is fascinating but as I have never done such wiring slightly bewildering to me. I do use a battery operated fan inside the frig but it does blow upwards. Your 12v fan provides more cfm but might the battery operating fan do a creditable enough job? As for the backside of the frig I also use a 120v fan but can only use that when plugged into power (or running the genset). There are outlets back there to be used and again this is much easier than wiring in 12v wires for this dummy...When rolling down the highway I am counting on air circulation to keep the frig running well...If using the genset for cooling one could plug in the fan for the frig... Mike 2000 Allure 30493 On Fri, 29 Aug 2003 19:49:52 -0000 "rvrobert2003" rkumza@...> writes:

Re: Dometic optional Thermistor Adjuster reduces refrigerator tempe

Reply #4 –
Yahoo Message Number: 6029
Thanks Robert, this will be my next project...
Tom

02 Allure 30780

Re: Dometic optional Thermistor Adjuster reduces refrigerator tempe

Reply #5 –
Yahoo Message Number: 6087
Good fix, Robert.

Have you thought of tapping the 12vdc at the refer light?
And, BTW, my temp stays around 35°F on the second setting from the left. At third setting I get ice on the fins. Outside temps of mid 80's.

Dick May

2002 Intrigue, #11438