The link above, and this one for the main wire harness.
http://www.bikebandit.com/houseofmotorcycles/1999-honda-valkyrie-interstate-gl1500cf/o/m151389#sch307109You need to turn the radio around, and plug it into the wire harness. Then try to figure out which leads are for know items, like the front head lights, turn signals, rear lights. Some components plug into other electrical items that are listed with the main wire harness. Then try to locate the connectors for the intercom leads radio link.
Then there is the good old fashion schematic, which will show you the color of the wires, and the # of pins in each connector. You can get that in any one of the manuals for the bike.