Fridge Doesn't work on AC

[donalie]

Wondering if anyone out there can assist in troubleshooting why the Fridge on my 17' Boler will not work on AC.

The fridge works perfectly on propane. It gets cold quickly and maintains an even temperature.
However I cannot get the fridge to work on AC.

1.The trailer is level.
2. The fridge is plugged in.
3. The selector switch is in the AC position with the thermostat at 5.
4. There is power on the terminal block on the back of the fridge.
5. There is 12V across the two blue wires on the back of the thermostat.
6. There is 12V across the white and black wires on pin 7 & 9.
7. There is a separate thermostat for AC/DC. Could this be faulty? How do I determine if it is the switch or the thermostat?

What should I do next? Appreciate the help.

[Harry Young]

Howdy from the high desert,

It would be VERY helpful to know make and model of the appliance over the stats of the trailer, the refrigerator if a three way uses a different tsats per class of circuit, ie. a 12 tsat for the 12v and a 110v tsat for a 110v too...if its a two way 12v/propane or 110/propane it is different.

If the tsat is closed (on call of cooling) then disconnect all power and turn off the gas and test for continuity, a twelve volt (battery powered "self contained power") light indicator style auto tester will work or a volt/ohm/continuity meter...if you get continuity or the light glows then move on to the wires leading into the pilot box, there is a heater in there usually 200 watts to 400 watts depending on your size of cooling system and voltage of heater element/ elements, its a round silver cigar about 3 to 5 inches long and poped into a neat tube soldered directly to the right spot on the refrigeration system, test the two wires coming out, if burned out it will 98% of the time show no light or infinite resistance (open) "you must disconntect both wires to test" You then need to replace it. There will be two of these in the case of a dual voltage unit, one for each voltage. I have found that old cracked wiring at the terminal block can be a simpler fix and should be looked at first.

Next... on some models you cannot run both gas and electric because there is a MECHANICAL interlock system excluding or denying one system from running when on the other system...On other models there is a manual toggle switch for operator switchover...If yours is a toggle, test the toggle switch and is connections...If this has a cam/tab sytem be sure what position is the cam/tab...some really old ones use a microswitch against the cam...Alot of the time I am patient with new owners of old systems because the guys who built them did not use the same play book so individual attempts of manufactures to be crafty confuses new owners...the cowboy manufacturing process in the old days ment variations...really look at this area.

Harry

[KevinDR]

donalie:

Welcome to the wonderful world of Dometic Refrigerators.

If yours is a dometic RM360 frig, like in my Boler 17, try the following link:

http://www.kitchenmanuals.com/manuals/mfg/...760_rm1300.html

This should get you the complete service manual for the fridge.
If my memory serves me correctly, when you set the fridge to AC, 120VAC gets fed directly to an AC heating element. It should be an easy trace. Trace the 110V cord and at least one of the wires will take you to the heating element. The Manual quotes the following:
"For the AC mode you should have
continuity between 4L and 4A and 5N and 5A.
If you find lack of continuity in any mode when
making these checks, the switch is defective
and should be replaced."

There is also a separate heating element for the 12V source if you run on 12V.

[donalie]

Thanks for the help. Scribbled on a manual for the Boler is RM36 so I believe this to be the model. I will follow your suggestions and let you know the results.