You now have two pos wires from the converter-red and blue to the fuse panel. The new converter will have one pos wire to the fuse panel.
So jumper the two pos connection points on the fuse panel (on the back usually ) and attach the one pos wire from the new converter to one of those pos connection points. The lug with the set-screw same as where the battery wire comes in allows for fatter wire from the converter.
1. 1991 Oakland 28DB Class C
on Ford E350-460-7.5 Gas EFI
Photo in Profile
2. 1991 Bighorn 9.5ft Truck Camper on 2003 Chev 2500HD 6.0 Gas
See Profile for Electronic set-ups for 1. and 2.