The large wire has currrent all the time, I'll have to check other wire though.It's drivivng me nuts

I had this same problem after I bought my 72, the previous owner had added a fuseable pull out 30 amp wire that ran from the starter area to the steering column. The fuse was blown, I replaced all my wiring in the engine bay and noticed the replacement wire for the fuse had a factory inline fuse into it. I would track down your wires from the engine compartment back to the fuse box. Good Luck