Gary welcome to the forum and irv2.
Here is a Brochure
and Owners Guide
that may have some fusing in some diagrams end of guide, nothing in there just coach wiring a fusing.
Below in my signature are links to many more related to Newmars.
The Ford forum
may help you out those fuses would be part of the chassis wiring with fuse banks under the dash left side of steering on in main fuse box on fire wall.
You may want to check the wiring in 7 pin plug rear of coach wires can come loose a short to ground in plug blowing the fuse, the plug wiring is in the OG.
For reference only this link
has 12v fusing for gas coach to you maybe able to reference too.
Keep us informed as to how you make out.