My 73 use to pull the same thing, try checking the wiring loom under dash for \broken / cut wires Then proceed to steering col plug in and look at the connection almost in center there should be a 10-12 gauge wire mine was melted and green, I jumped past it and she starts right up, next Fuse box you may just want to get a parts store box and eliminate the stock one with the glass fuses the fuse connections are generally the problem they aluminum corrode and the fun begins. I only do that as a last resort when I have had enough of being under dash