Troubleshooting Dometic RM 4223

[BigCat77]

Hi all,

Im trying to troubleshoot issues with our Domestic RM 4223. This is my first time testing the fridge as the Viking 2470 is new to us.

When switching to 110V it immediately trips the camper GFI, if I plug directly to the house it trips that breaker as well.

When switching to 12V I hear the converter fan kick on but nothing kicking on with the fridge. Not sure if I would hear anything like a traditional compressor fridge, this is the first time testing it.

I tried to start it with propane, I was getting spark but no burn. Im actually going to try on propane again today while its less windy out.

Any other suggestions to look for is greatly appreciated.

Thanks,
Forrest

[Chris_Bryant]

I have seen elements trip a gfi when cold, then work fine after heated by the lp flame. Not sure if it was a bit of moisture inside the element leaking just enough current to trip a gfi.

[BigCat77]

Yah, I tested the element disconnected. I went through all the connections and everything looked fine.

I however did find the issue. The house outlet I was using I thought was a 20 amp but it turned out to be a 15 amp GFI breaker (outdoor socket). After keeping the shore line plugged into that I then plugged the fridge into a outlet on a standard 20 amp breaker and its working fine.

I swear I had tested different outlets before but either way everything seems to working as should.

I appreciate everyones help and I have learned a lot with your assistance.

Thanks again and safe travels,
Forrest

[jkwilson]

Did you disconnect the element from the circuit when you measured?

Even at 90 Ohms, the element only draws 160W which is 1.33A so not likely to be a cause of tripping a breaker.

[BigCat77]

Ok, I probed the 2 white wires and its reading 90 ohms. Parts list state it should read between 108 to 132.

Would a weak element cause the issue of tripping the breaker or just not cool the unit? Later Im still going to pull the switch mount and inspect further for loose or open connections.

[red31]

probe the two white wires for ohms, the green/yellow is ground.

[DFord]

When operating on electric, it doesn't make any noise but the tanks accessible through the outdoor service cover should get warm/hot! Be sure you're level both side to side and front to back. I doesn't take long to overheat and cause trouble when not level.

[BigCat77]

I also notice that its possible the AC element has been replaced before because the part number is written in pen on the back of the manual so hopefully its just a ground issue. I didnt think to look for the 120v ground wire while I had the cover off. Per Bud's suggestion I think Ill unscrew the entire switch plate and take a look after work.

[BigCat77]

I was able to successfully get it running on LP and it starting to cool down.

There are 2 elements going into it and it appears there is one to the DC switch and one going to the AC switch.

The element going to the DC switch has 2 wires, where one goes directly to the switch and the other down to a ground block where there is a pigtail fuse coming off of it and it appears pos and neg from the converter.
I think i need to pull out the other wire to successfully test resistance on that element.

The element going to the AC switch has 3 wires, 2 white wires and one green wire. Im not sure how to test resistance on these so Ill keep searching the inter webs.

There doesnt appear to be any burnt or loose wires from inspecting so far.

[enblethen]

You need to test the 120 volt element to ground.
It is more likely grounded where the wires enter the stack.
Look closely at the circuit board for any burnt areas around the 120 volt relay. Removing the circuit board and looking at the back side would be beneficial.

[BigCat77]

Ok, Ill test that. Thanks.

[red31]

I'd disconnect the 120v AC heating element and checking its resistance, 120 ohms page 2

http://www.giordanobenicchi.it/camper/manuali%20vari/dometic_RM4223%20Parts.pdf