Check out page 10-6 of the operator manual:
It describes it as being located "under the hinged instrument panel pod".
You'll probably find additional fuses located under the hood where there may be some sort of master protection. If you have more difficulties, your best bet is to contact a shop that services your chassis (Chevy?). Originally your coach would have had a chassis manual.
There is a wealth of information (parts manuals, wiring diagrams, plumbing diagrams, etc.) on your coach available online at:
(Detailed list is in the lower right hand corner of the above page under "Manuals and Diagrams".)
Also, if you create a signature that includes the specifics of your coach (see mine below) we'll have more information so we can make specific recommendations. You do this under the "User CP" tab in the bar at the top of the forum page.