I had the same prob with the tach except I got smoke and a funny smell. I took the wire off the stud/nut and ran it into the tach slot on the plug # 14 if I remember, made my own little connecter for the plug,it just has to make contact. The capped off green plug under the hood did not work for me on my 83 I did the same thing KYOTA did in his pic. I doubt the cluster is bad I smoked mine and it still works great. Let us know if you get stuck, many have done the swap and are happy to help.
