How make not working tail lights or brake lights not working 2000 F150

If you mean the tail lights and brake lights not working. Check light bulbs, if light bulbs are ok, check the wire harness connector under bed by spare tire. Brake lights also have a switch riggt above the brake pedal tha might need to be adjusted or replaced.

note the diagram for hi mount stop lamp. Note brake pedal position switch, In the diagram, top wire is voltage, fuse protected, Check fuse, use test light, check voltage on that wire going to brake pedal position switch. When the switch is activated, check voltage on the bottom wire, in diagram, again, use a test light. see the hi mount stop lamp in diagram, the top wire is voltage, the bottom wire is ground, check them both.