only one light with emergency flashers??

[bigmoe]

So my 65 C10 is a frame off LS restomod. I fully rewired it. Yesterday the last thing to finish was the tailights. When I connected the battery I put the four way flashers on to check the four corners and it immediately blew the fuse. With a new fuse I tried signal lights first. Right worked. Left blew the fuse. Anyway long story short I discovered in my left rear aftermarket light the socket wasn't properly seated from the back and the two electrodes bent over and were touching causing the short. Now absolutely everything works EXCEPT when I tried the fourways only the front right flashes. Flasher is clicking. Not sure where to start with this one except it must be under the dash because all the other lights function properly. I hope it's not in the new column. Any ideas?