The 48 and 49 ought to have a fuse block with 5 fuses and one solid (non fused) connector. The 4 fuses are Upper Beam, Lower Beam, Park, Tail and Stop. The solid connector is for the horn. The 50 and 51 ought to have a fuse block with 2 fuses...stop and tail. Sorry but I don't have a wiring diagram for the 47 and the data I have on the 1952 shows it is basically the same as the 50 and 51. I mention the 48 and 49 because years ago a friend had a truck titled as a 1950 which was actually a 1948 cab on a 1950 frame (with the 1948 wiring). We don't know when it happened, but it did and the title was never changed.

~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end