Dead Radio, Backup Camera, Navigation

Need HELP. Picked up RV from storage this morning. Backup camera worked, radio was playing. Halfway home it quit. Husband and son checked every fuse they could find under dash and under hood. Checked for loose wires....nothing. Can anyone tell me what else to check?

Check your Ford owner's manual.   There is a fuse panel at the left side that has the radio fuse.   Not the distribution panel in the engine compartment.   The below link will bring up the distribution panel first, scroll down and it will tell you where to locate the inside fuse panel.

Should be fuse 39

https://www.autogenius.info/ford-e-450-fuse-box-diagram-power-distribution-box/amp/

We checked all the fuses under the dash on the left as well as those in the engine compartment. They were all good.

The thing that is common to all that suddenly quit, is the radio.  It either is not getting power or has died completely and needs to be replaced.

Not getting power is either a fuse, or the power harness to the radio.  You'll have to pull the radio to insure it's plugged in and to check the harness has 12v on its power feed.   If you don't know how to get the radio out, then I would suggest you go to a car radio installer nearby and have them check it out.