My fridge has stopped working on DC. I get no voltage at the fridge fuse
on the drivers door pillar but I do get 12v on the 2nd fuse that powers
the fridge fan, Led's, etc.

The power to both of these wires comes from the relay in the 2nd battery
box behind the drivers seat. Just to eliminate a bad wire I took a
reading direct from the relay, nothing. 

I'm thinking the relay has gone bad, am I on the right track?