My 2014 Rockwood Windjammer 3008W has a Dometic DM2652LBX refrigerator. (Side note: when this problem started I dug through the large pouch of manuals and discovered I was only furnished an "operating instructions" manual for a Dometic RM2620/RM2820.
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Any way we started having problems during a five night stay in NE Ohio over Memorial Day weekend where the temperature inside the fridge was mid 40's at best. The temperatures that weekend at our location ran mid to upper 80's day time. I researched and found that was rather normal for absorption refrigerators and first read here about adding cooling fans. we had a very similar problem under very similar weather conditions on a trip in early July, but I still took no action. blaming it upon the hot weather. The first week in August we spent 8 nights at our county fair where the weather turned into upper 80's low 90's daytime and low 7-'s at night. BTW We only have a 15 amp supply at the fair so no AC's are allowed. this week the fridge temps. started in the 40's but gradually increased into the upper 50's. (Good thing for fair food as we disposed what food was in the fridge.) Upon returning home I delved into the problem with earnest. I read as many posts and articles as I could find and decided to first check the thermistor. At room temp. (~76 degrees as far as I could tell) the thermistor read 3.058K ohms and after 30 minutes in an ice water bath it read 7.07K ohms. Not the 2.857K and 9.37K ohms that I found on this chart:
Thermistor Values for most Dometic RM & DM Models, but seemed reasonable. I read one article, which I neglected to bookmark and cannot again find, that recommended unplugging the leads to the heater element from the control and applying 120 vac directly to the heater leads. Let it go 10 to 12 hours and if the refrigerator gets cold, the problem is not with the actual cooling unit. After the time frame my fridge read 30 degrees and the the water in the cup holding the thermometer was frozen over. Great news! I decided to replace the thermistor with this unit:
Snip The Tip, and the next morning after the install the temp in the fridge was 38 degrees with overnight temps right around 70. (Just for comparison I put the thermometer in my home fridge and it read 39.) Later in the afternoon the temp. was 40 degrees with outside air in the low 80's. My conclusion was the thermistor was faulty enough to cause the problem compiled with the hot outside temps. At this point I have ordered and received the same 12 VDC temperature controller as posted in another thread by TURBS and have ordered two of these fans:
140mm-25mm-Case-Fan-12V-DC-153CFM-CPU-Computer-Cooling-2-Wire-Ball-Bg-14025-409, to install in the roof vent. I will update after I get them installed and tested.
Sorry the post is long, but I though the info might prove helpful to some people and thought everyone should know about the test putting 120 vac power directly on the heater.
Linear Mode
