The thing to remember with a 3 way fridge is 12V for driving, 240v for van parks and gas for off grid................. If you haven't got any manuals in your van get the brand and model number of all the things in the van, ask Mr Google and download, print and put them in a folder to live under your seat in the van, after reading them of course............ The Dometic Fridge Instruction manual and the Installation manual are very good and will give you a good idea what they are about as well as allowing you to check that it was fitted properly the first time..../ The Setek manual is pretty basic but does at least show you whats what, again checking that the fuses actually match the tags is a wise choice before things blow......
If you have a 12pin socket on your van it possibly has the circuit hooked up which will run 12v from tug to fridge and Setek unit, while this works okay its not the best for the fridge to get a decent supply of power while driving down the road.......this is part of the reason why folk disconnect the fridge from the caravan wiring and run their own dedicated cable from an anderson on the draw bar to the fridge, not hard to do any doesn't need half the complicated things some say to do, just remove the van 12v wires from the connector on fridge, fit a Fridge Switch to connector then your own cable to the fridge switch , leave the 12 pin alone, hooking up to tugs power is dependant on the tugs set up but the fridge switch fitted will stop you draining all the power form your tug when you stop and forget to unplug the anderson.........you use an anderson because once you fit the things you rarely ever have to revisit them..................of course there are other ways but thats the least complicated, always keep your mods simple, Kiss is always the guide rule.
If only have a 7 pin then leave it alone and just run your fridge cable as above, it still might have a 12v supply to run to the Setek and charge a battery, how do you test this out well with eitther a 12pin or 7 pin, just disconnect vans battery, plug in to your tug, start engine and then see if your vans interior lights work, if they do you have 12v supply to van from tug, if not then you don't or the wires has broken.
PS: It is imperative that the vans 12v switch is on or you will pull hair out trying to find the fault..................... proven and known FACT.
