1996 Georgie boy cruisemaster 34'

If it is blowing the Switch fuse it is probably an issue between the switch and the fuse block. Most of the rest of the items are fused separately and you should be blowing the individual fuses long before you blow a 60 amp fuse. I think one of the previous poster suggested that you pull the switch and test the lines to determine which one has the bad leg. You may have to trace a couple of junctions if it off your accessory leg. I have had similar issues with various vehicles over the years and most turned out to be a pinched or abraded wire under the dash, several but not all were steering column pinches.

Disconnect the batteries
Pull the fuse
Crawl under the dash and start measuring resistance to frame ground on All wiring connected to the accessory circuit
This could include stereo, heater blower, a/c etc...
Even relay power to the hyd levelers
The one with zero resistance is your short
You might need an extra long wire to go out a window and connect directly to some chassis steel for the frame ground connection
Get an f53 Chilton manual to help yo find the accessory fuses and wiring harness connections

its the switch itself shorting out to ground try using just 1 key not a bunch of keys hanging.Sometimes its the wire itself at the ignition