If it's not in the main breaker/fuse box, then I would look for an in-line fuse around the motor assembly.
Also, the electric steps may be considered part of the MH frame, so check the MH chassis fuse box in the engine compartment and/or under the dash.
2016 GM 2500HD 6.0L/4.10
2005 Jayco Eagle 278FBS
Reese HP Dual Cam
Putnam Class V