Using Upfitter switches to power my extra frig on the road?

the 0.7 at 120v is 7.0 at 12v make that 8~9ammps 12vDC with conversion losses included

but you need an inverter that will carry the compressor surge load spike on start and that might be more than 500w

I'd go the inverter route as well. Dorm fridges don't draw that much power. I just put my Kill-A-Watt on my 'counter height' fridge we have in the basement rec room and it pulls about 55 watts/.7 amps. You don't need a big solar bank for that but just be careful how long you are running it as you drive so you don't drain the battery. Also not sure how much the truck will supply to charge the battery so might want to be careful the first time. A 500w inverter with the proper size wiring should do the trick.

If you want to run it while you are traveling, you probably shouldn't power it off the RV battery unless you have a big solar bank. So the solutions described above don't seem feasible.

Check amps on the fridge. Whatever it says, your wiring will need to handle 10X that much for 12 V power. Plus you will have some conversion loss through the inverter. So be sure your upfitter circuits can handle that much current.

KD4UPL wrote:
What you're proposing could be done but is probably the most complex way of doing it.
If it only runs on shore power then it's 120v AC, not 12v DC which is what you get from "upfitter switches". You would have to have an inverter somewhere to make the 120v AC. If you're going to install an inverter you might as well be able to use it for other things in the RV, like maybe watching TV with no hookups.
The simplest place to connect the inverter is the RV battery bank, not a switch in the cab of the tow vehicle. That would result in a long wire run that would have to be fairly large wire to handle the current and distance. It would also require and additional electrical connector between the truck and trailer.
Just put an inverter in the trailer, connect to the house battery(s), and wire it to the refrigerator outlet plus maybe a TV outlet or something.

You would be better off installing a small 200W to 500W invertor, than using one of your Upfitter switches. Less power loss.

What you're proposing could be done but is probably the most complex way of doing it.
If it only runs on shore power then it's 120v AC, not 12v DC which is what you get from "upfitter switches". You would have to have an inverter somewhere to make the 120v AC. If you're going to install an inverter you might as well be able to use it for other things in the RV, like maybe watching TV with no hookups.
The simplest place to connect the inverter is the RV battery bank, not a switch in the cab of the tow vehicle. That would result in a long wire run that would have to be fairly large wire to handle the current and distance. It would also require and additional electrical connector between the truck and trailer.
Just put an inverter in the trailer, connect to the house battery(s), and wire it to the refrigerator outlet plus maybe a TV outlet or something.

You could add a small power inverter easy enough and pretty cheap too.