I have a 2000 crown vic police intrerceptor. no power to 4 way flasers, gauges in dash, radio,trunk poper button,diagnostic plug ,or the fuel pump, but turns over, iv,e replaced lighting control box and ignition switch, what else could it be.?

I would check all the major fuses. Sounds like you might have one or more of them blown. Also check fuse panels for feed power.

Your vehicle is equipped with 2 Fusible Links that supply power to the Junction box. A Fuseable link looks like most any other wire with the exception that insulation is a little softer and the wire inside is designed to burn apart when over loaded. They should have either a tag or writing on them that indicates "12 GA Fuse Link" They are taped out of a main wire loom and connect to the Battery Junction Box (under hood fuse box). Just give them a tug, if either is burned, it will come apart easily. This is my best guess based on the common power feed to all of the components you listed. Hope it helps.