I would follow the wires right back to where they are spliced into wiring harness,and eliminate them there and also check wiring harness in that area, that being said i would also trace wiring harness to the tail lights if you are still popping fuses. when you heard fuse pop immediately what was on in vehicle,did you have signal light on ? left or right . If wiring at back looks good check the front also . If it is one side only popping the fuse you got half the battle beat