Yeah, there's no way around it--you have to figure it out. If the boot's switch is accessible, maybe you can remove/disconnect it and check the wiring from the battery and the wire going to the lamp, then check the switch itself and make sure it reads 0 ohms when closed. If it's a bad wire from the switch to the lamp you might be able to splice a new wire in there. If it's a bad switch then see if it's possible to disassemble & clean it or find a new one of similar type.