I can't see how your fridge or battery warranty would be affected by changing to an Anderson plug and presumably, a 7 pin flat.
If you are following the wiring instructions with the correct (recommended) size of wire the manner of connection is up to you.....and is flexible. Jayco do their standard 12 pin plug wiring and, as long as you connect the correct wires, as identified from their plug, to the relevant car wiring, you should be fine.
If not, I'd be interested to know why not.
Are you getting an auto electrician to do it? If so, take the 12 pin wiring diagram to him so there's no possibility of error.
There's a 12 pin wiring diagram somewhere on this site ...just do a search and yell if you can't find it.
Good luck with the anticipation and reality of the new van and all the little annoyances that come with it....it's worth it in the end.
