looking thru the 456 manual in the fuse section (Page L21), one column has A20, A25 A10, A7,5 , ETC those would be the fuse rating for each circuit ? A20 = 20 amp ? just checking.....
As you already know (owner's manual) fuse #4 controls Luggage Compartment + Roof Lights + Cigarette Lighter + Daytime Flasher Lights. Fuse # 5 controls the "A/C Group". Diagrams? Pfft, on the Ferrari assembly line they didn't need no stinkin' diagrams...!