Swap 12v for 120v Fridge Element? UPDATE 2

The 12v element is only 12v
It will burn out if you connect it to 120v

Disconnect the wires and measure the resistance with the OHM METER on your multimeter, should be something less than 2 OHMS

If you connect that to 120v and you are going to weld it in there ,

The 120v element is 240/300 watts aka just over 2 amps at 120v , or approx 50 OHMS residence

YOU CAN CONNECT the 120v to 12v it will not work and nothing will happen
You CAN NOT, do the opposite, the 12v element will burn out

I had a job maintain and repairing machinery for plastic welding that used various heating elements,

I think it's one of the safer assumptions that the elements are different. Just to double check that, I looked in the service manual for Dometic Americana friges. For the 120 volt element, the cold resistance is either 44 or 80 ohms (depending on fridge model), and the 12 volt element cold resistance is between 0.67 and 0.96 ohms, depending on model. Applying 120 volts to the 12 volt element would pull an initial 125 (or more) amps until something melted.

ScottG wrote:
Jus tusing math to calculate wattages between the two elements, I would say they are not the same resistance.

I am not sure of the logic, but I am wondering if the 12v one is doing only 132w because that is what it is being fed. Leaves open what it could do?

What would happen with the 120v--would if get too hot? Would it just pop the 120v breaker from too high an AC current?

Jus tusing math to calculate wattages between the two elements, I would say they are not the same resistance.

Thanks, I will see if I can shift the 12v one at all with some spray there.

My question is whether the 12v element is only 12v because that is what it is being fed, or does it have a part inside it that is 12v that would fry on 120v? I doubt wire gauge is an issue here?

Is it like a cigar lighter in the dashboard? Those things get red hot on 12v and ISTR are about 20 amps. This has a 20 amp DC fuse.

EDIT--I broke off that 120v one where it is cracked. It is a hollow brass tube, with white hard material inside with some sort of ? threaded like a bolt--rings anyway--part down it. I guess the two wires going in the top end attach to this inside piece somehow.

I can't move that 12v one even after spraying it. Can't get the bottom part of the 120v out of the sleeve/boot.

I must decide whether to try the 12v on 120v (but without that 20 amp fuse) or just have 12v and gas as options. Perhaps I can do the pre-trip day's cool down on gas, switch to 12v on converter overnight, then back to gas for camping next day. (Only use the 120v for pre-trip cool down at home--always on gas for camping)

When I changed my 120 v element I noticed the same thing. I had to spray the element with PB blaster and work it back and forth with a needle nose pliers because the rust was so bad. It eventually came out and I cleaned the hole out with emery cloth before installing the new one. I believe you can remove the 12v element and install the new 120 v element in its place if you can't get the old element out but can't see how a 12v one would work off 120 volts. Do you use the 12v element?

The 12v works at the moment. It pulls 9.7 DC amps according to the Trimetric. The manual says it can't do an initial cool-down, only good for keeping it cold for 4 to 6 hours --but that is battery saving advice I think.

I was thinking they are the same metal part-look the same, but one just has less power on its wires when getting 12v instead of 120v. I don't use the 12v , so if it fries no loss.

I can't move them so I don't know how I would replace that 120v one. I think maybe they drop into that sleeve boot thing but now are rusted in there. Not sure how it is supposed to work to change them.

I could just try it and see what blows up or doesn't, but first I hope to hear from somebody who knows fridges.

Applying 120 volts to a 12 volt resistance heater may let out the magic blue smoke.