Stu, I just couldn't help noticing that tomorrow (Sept 10) will be the 6th anniversary of your post noting that you had learned your lesson about always checking all the connections, and that your fridge was working again. Time has a way of getting away from us, doesn't it?
You did well to go all the way back to the distribution panel looking for problems. Since 6 years ago, I have had several of the original rocker switches cease to function under any load on my boat. This has happened most recently on the fresh water pump switch. I replaced the function of that switch with a much more robust toggle switch with screw terminals which I mounted in the outside edge of the distribution panel adjacent to the failed switch. Quite honestly, the panels on the earlier boats were awful! On my boat, there is a mismatch on several places between the push-on spade terminal sizing and the spade on the back of the switch: the switches had 3/16" wide spades, and the push-on receptacles were 1/4", sometimes with some extra mashing around on them to make them
sort of stay on the switch spade.
Having said that, as long as you have completely replaced all of the wiring to the fridge, don't overlook that first possible culprit in the wiring chain, the switch.
On my ever-expanding boat project list is the complete replacement of the old distribution panel to achieve no push-on terminals anywhere, no wimpy switches, and no rat's nest of wires to the extent that is possible.
I hope your good work and dedication to the task is successful. Maybe on the 7th anniversary of this topic, you can happily report a year of reliable fridge operation