Swap 12v for 120v Fridge Element? UPDATE 2

You asked about the refer 20 amp fuse the SUPPLY larger fusing. The reason is simple. Dometic expects the 10 or 8 gauge wiring to be used. Once the 12 volt dc hits the refer, the 20 amp fuse is more than sufficient to protect the refer wiring. I have rarely found the supply wire gauge to be to spec from the OEM. The ONLY OEM I have seen that actually supplied an 8 gauge wire was the old Chinook motorhomes. Most others used the 10 gauge IF they used that large a wire. I have seen a lot of 12 gauge over the years. The operation of the Heat elements is very SIMPLE(120 or 12 volt). ALL they do is react to the incoming voltage and heat accordingly. That is all they do. They don't pull less volts or watts depending on the refer cooling state. They just come on and OFF from what the Tstat tells them. I would NOT run my refer on 12 volts on a regular basis f you cannot get the 120 side fixed. They are NOT designed to run exclusively on 12 volts. As the manual usually states, the 12 volt option is a MAINTAINER of existing temp and is supposed to be utilized when the Tow vehicle or motorhome engine is ON and supplying 13.2 plus volts. Doug