WTB 521 full wiring harness

I don't have for sale, but I'll see if I can see the part # tag on my 1972 dash harness, so you have a better chance of finding the exact one!  If you can't find another harness, but you think you can repair yours, I WILL have a couple 1970-1972 510 dash harnesses, that you MIGHT be able to use as a donor harness to repair yours, as they are from the same era, so might be same color codes etc.......??

Check out vintageconnections for new plastic plugs & the correct terminals!  They do NOT offer by application, but go on their webpage & you can choose VISUALLY.............you just need your old plugs to compare.

02'70 to 05'71 instrument harness is 24013-B3120. Good luck finding a new one. A used one is (besides hard to find).... used and could be more problematic than what you have. 

90% of electrical problems will trace back to a corroded fuse box with poor contacts. Before anything else, I would label all the wires and remove from the fuse box. Thoroughly wash the fuse box to remove any grease and soak (submerged) overnight in a mixture of straight lemon juice and dissolved table salt to remove any trace of tarnish. Wash and dry and inspect. Check that the fuse holder clips are clean, springy and have good grip contact on the fuses. Are the wire connections and screws any good? Might as well get a newer replacement with blade fuses and crimp new ends on the wires than deal with a piece of crap.

I would remove the harness you have and carefully inspect it. If, there are signs of melting, the wrapping must be removed entirely and wires separated and checked, replaced where needed. For simple previous owner tampering and splices, the most likely thing, get a good wiring diagram that has the color codes clearly marked and put the wiring back to stock.