My 99/2000 Conquest Class C floor plan puts my panel at knee space under sink, your floor plan may have different location. Is yours a C, or trailer? Breaker/ fuse access has small square plastic finger 1/4-turn latch at top of BROWN METAL hinged cover. MIGHT BE DINETTE BASE, BED BASE OR BATH?
2000 Conquest LE 6266, Class-C on 99-E450SD, 6.8, 2v, V-10