blown park tail fuse and no dash lights

 The other night when I turned on the headlights I had full lights for 40 seconds to a minute, then I lost dash lights. I checked the fuse and it was blown and the passenger side taillight was burnt black the filament was still intact though. When replaced the fuse burns instantly. I have function of headlights, break lights, turn signals, and warning lights. I have disconnected the entire dash assembly save for the head light switch. The rear harness is disconnected ,the door buzzer, there are no lights in the back of the car, and the dome light is unplugged. The fuse still blows immediately. I have run out of ideas any help you guys can offer is appreciated.   Thanks.