8 CF single door Dometic fridge cooling issues

[Yoda]

Dometic fridge
MFG # 958687054
SR# 73698-497
MOD# DM2682RBFX

I installed the aux cooling fans before the trip and noticed an immediate improvement over the last use. I wired them in with the stock fan switch so when the limit switch activated all fans cam on (stock single and two Aux)

On the first part of the 5 week trip I was running 4 on gas and 3 electric and had to watch to keep from freezing the fridge. Freezer stayed between 2 and 8. Midway through I was up to 5 on electric and 4 on gas,but performance was dropping. (freezer went to 10 to 18 and fridge was running high 30-low 40s) . The big concerned was the day before we stopped north of Salt Lake at the A-frame campground. On 5 electric we were hovering around 43-45 on the fridge and freezer was at 20. I did not notice the fan issue at A-frame. Overnight the fridge temp did drop to about 38 and freezer to about 18. At Salt Lake the outside temps were in the low 90's and fans seemed to be running intermittently or not at all when previously they would always be on at throes temps and fridge was at 46 and freezer 25. So I bypassed the limit switch and got the fans running constantly. That got the temps in the fridge down to about 42 and 20 in freezer. On the second day I switched over to gas only - had been on electric (setting max at 5) and got it to drop another 2 degrees.

Now freezer had built up some frost (1/4") and fridge fins had a minor bit of icing once in a while, but mostly just condensation. Fridge temp probe was on far right between the last two fins - I also tried it clipped just to the last fin that seemed to help.

Last day fridge started at 40 from overnight on gas and freezer was 18, but when we got home after 8 hours of driving fridge was up to 44 and freezer up to 20. No doors were opened during this time. Truck and trailer tow fairly level, maybe 1.5" high at the king pin, but only 1/4" high at the shackles. I think the fridge was made in 2017 nd is in my 2018 model

All during this time I also had a fridge fan cube running in the fridge. It seemed to help when running, but did not like rough roads as batterys would pop out of place. https://www.amazon.com/dp/B09GCH9ZZZ...roduct_details Fridge temps were being monitored buy this set up and it worked well https://www.amazon.com/dp/B07XD68GX6...roduct_details.

Thoughts where to turn next. BTW never an ammonia smell. Can the system be recharged?

Thanks for any input

Keith

BTW I know there is a diagnostic check list here somewhere, but i could fin it this morning.

[Jlawles2]

If you have an ammonia leak, there will be a powder discharge. Dad had to pull the refer out one time, flip it over while off, and let it sit for a few days (he forgot so it went a couple of weeks). flipped back over, waited 24 hrs, and she went back to normal cooling.

BTW I think there is a charge port on the bottom of the ammonia cooling coil on the back where the big storage bulb is located (at least in the old days there was). Looked similar (going off memory here) to the top of the small propane bottles.

[howson]

Yoda -- been down this path with absorption refrigerators. Only long-term "fix" (for me) was replacing with a residential refrigerator.

Also, there's no way to recharge an absorption refrigerator. If the cooling unit goes bad it is replaced.

[Yoda]

Jlawles2 howson

Thanks guys. Do you know if one of those interior fan set ups that attach to the cooling fins work? Like this https://www.amazon.com/dp/B072BPYXS8...f_=as_li_ss_tl

Just wondering I really don't want to replace if I can as I like the propane option when traveling.

Keith.

[Jlawles2]

Keith, have you looked into https://rvcoolingunits.com/ ??

[Yoda]

Is there a way to check the limit switch? It looks like it should activate at 104 deg. I was thinking of using my heat gun if it goes that low?
They are pricey - cheapest I found https://www.boatandrvaccessories.com...ch-replacement

Thanks
Keith

On edit - Dometic got back to me on the part number and mentioned about the temp probe placement on the cooling fins - mine fell off at one point on the trip - something I did not know. I need to check the position it is in now.

"The thermistor sensor should be on the far right fin, you are correct, if you would like your fridge to run cooler move it up, for warmer move it down"

HMMMM - I wonder if I just found the problem. The sensor was in the lower part of the plastic clip and the clip was below 1/2 way puting the sensor at the bottom of the fins..I think so testing is in order with filled water jugs, etc. We have some hot days forecast next week..

Another edit - found this great video and a tip to keep it in place. https://www.youtube.com/watch?v=Gsihtpi_kqc&t=37s

Another edit found this too if all else fails https://www.dinosaurelectronics.com/Dom_adj.htm