This places most likely the tank bay rear bulkhead. Passenger side aft of the rear storage compartment, or before the rear wheel on that side, open up that door and look above on the rear wall, it has a couple of fuse blocks if it's a newer coach.
Please modify your signature showing the year and model of the coach so we can see it at a glance, please look at mine. Assuming yours is a 40 FDTS or like that, the above will let you know where those fuses are. Please note, they can be the large ones, the small ones or maybe medium ones, Don't remember which one is the WP, or the indicator panel one, as I don't have that feature you have, mine is silverleaf data fed.
Monty & Janet - 2007 Alpine APEX 40 MDTS
S/N - 75715 - Retired - Master Certified RV Tech