On the '06 Dynasty, it's in the rear run box on board #4, and is a 20 amp fuse. Not where you'd expect to find it, but that's where it is on ours.
If the macerator overloads, it will slow, and when it slows the current goes up. If it stays elevated long enough, the fuse will go. I hope you can re-fuse it and get it to clear. We had ours actually stop on its maiden voyage, and it required disassembly to the point where I found an electrical staple in the macerator blade. Not a fun job!!!
Jim & Angie, Boise, ID
2006 Monaco Dynasty Countess III
2017 GMC Acadia Denali