Dometic Refrigerator not cooling properly

[Pocketlake1]

We have a Dometic gas/AC refrig. Unit is a little over 2 years old so naturally warranty is expired. When running on gas it works perfectly, but when connected to shore power and opening / closing frig the temp creeps up to 50 and will not cool down. Switch to gas and it gets back to 36. We then switch back to shore power and as long as we leave frig closed, leave it alone, it will stay at 36. Soon as we start opening/closing, normal dinner time activity, temp creeps back up, eventually to 50, and won't cool down unless we switch to gas.
Also when On shore power it always seems to run, does not cycle on/off, although it is somewhat inconsistent, and sometimes will run run perfectly for several days when on shore power. Any opinion on What the issue may be?

[Starmaster]

You did not say which model/size the frig is. Im guessing its 10-12 cu ft or larger. These usually have two electric heating elements on the boiler to supply heat when the frig is running on electricity. Since it works OK on propane, I'm guessing you have one of the heating elements that have went bad. That could explain the working, but not well situation.

If you or a friend have some electrical troubleshooting experience and an ohmmeter, you could test the heaters. They should read some minimal resistance, I'm guessing 50 ohms or less. If one of them shows a high resistance or no continuity, that heater is bad and needs to be replaced.

Good luck!
Dave

[dieselguy]

You'll need a multi-meter and know the basics on how to use it. Download this http://www.fourwh.com/NewDometicRefrigeratorManual.pdf and go to page 17. Read about A/C mode and refer to diagram on page 14 for location of J5-8 terminals for testing. Alternately your 120 VAC heating element could be shot. With power off, unplug the wires going to it and check for continuity at those two wires. Refer to page 10 for this check. This may not get your answer, but it will eliminate possibilities.

[Pocketlake1]

Folks, thanks for the input. The frig model is RM1350SLMX. Seems an elusive problem and this gives me some good direction. Thanks. Very much appreciated

[jcurtis934]

If the two heaters have a reading, then it could be the electronics as well. That is easy to replace from outside through the lower opening.