Fridge doesn't work on 120v

[Wayne Collins]

We have a 2000 Scamp, 16 ft, SD DLX w/ 1.4 cu ft Dometic fridge.
It has stopped working on shore power 120 volts.
the 12 v side works as does the LP.
Has anyone else had this problem? How did you fix it?
WC

[Jack L]

It could be a power supply problem with the 120 volt circuit or a failed heating element. Heating elements are not too expensive and fairly simple to replace.

[Eddie Longest]

Open your frig. access panel. Check to make sure your frig is pluged into the duplex outlet. If pluged in try a light in the outlet, that will tell if the issue is in the frig. or trailer. If no light you could have a bown fuse in the converter.
Eddie

[Wayne Collins]

Thanks,
Been there, Done that. There is power up to the green switch. Can't get at the heating element without major disassembly..../wc

Originally Posted by Eddie Longest

Open your frig. access panel. Check to make sure your frig is pluged into the duplex outlet. If pluged in try a light in the outlet, that will tell if the issue is in the frig. or trailer. If no light you could have a bown fuse in the converter.
Eddie

[Paul O.]

I had a similar problem with the fridge working on Propane, but not on AC. It does not have the 12V option. It was not hard to get the heating element out. However, the plastic contact cover was impossible to slide out because of the plumbing running behind the fridge. I had to cut the plastic in half in place in order to remove it. I taped it together with duct tape when putting it all back together.

Note: after doing all that, the element measured OK and it started working, but maybe the connection was not good enough before and re-tightening fixed it.

[mszabo]

Not mistaken I believe the 120v and 12v element is the same element.
Make sure you have 120 volts at the ref. outlet.

[Paul O.]

Originally Posted by mszabo

Not mistaken I believe the 120v and 12v element is the same element.
Make sure you have 120 volts at the ref. outlet.

That means that 3-way fridge must have a transformer to take the 120 down to 12 Volts. Now I am curious and will try to look at some circuit diagrams.

[mszabo]

I don't think so. It uses the same element for both. At least mine does.

[Jim Bennett]

A meter will help you sort out the problem. I would first check that the plug works, then work my way down the line, ensuring the voltage is present when heat is called for.

It could be the element too. This can be checked by checking the resistance across it, with it disconnected from the circuit. If you don't know how many ohms resistance it should be, but do know the wattage of the element, it can easily be calculatted as the Resistance (ohms), is equal to the voltage squared (14,400 for 120V), divided by the wattage of the element.

I have had my thermostat go, and replacing it cured the problem. I found this out, as there was no voltage going to the element when there should have been.

[Jim Bennett]

Originally Posted by mszabo

I don't think so. It uses the same element for both. At least mine does.

I know in my 1976 Triullium with the Dometic RM211, it does use the same casing for housing two elements. There are 3 leads, one common, one for 12V, and one for 120V. On the original fridge, the 120V element was burned out, but the 12V worked fine.

I think this setup is quite common, though have only had to do repair on 3 different RV fridges before.

[David Tilston]

If your fridge uses the same element for both 12VDC, and 120VAC, then to keep the watts the same, the 120 V would be wired for the full length of the resistor, and the 12 VDC would only use 1/100th of the resistor, with 10 times the current on the 12VDC section. It seems more likely that two different resistors are in the same container.

[mszabo]

Jim, mine may have the dual elements also. It's been awhile since I have looked at it. Ring out the element, it will tell you quick.

[Paul O.]

Originally Posted by Jim Bennett

I know in my 1976 Triullium with the Dometic RM211, it does use the same casing for housing two elements. There are 3 leads, one common, one for 12V, and one for 120V. On the original fridge, the 120V element was burned out, but the 12V worked fine.

I think this setup is quite common, though have only had to do repair on 3 different RV fridges before.

This does make most sense, the heating elements are pretty cheap and it is simple to wire it that way, as you described.

[Carol H]

Should also simple be that a fuse is blown inside the converter.