1969 Mustang won't start

no common grounds. Thats about the only thing that I can think of where absolutely nothing has power. If you've got a multimeter test the posative point off the battery to various spots, the frame, engine, inside fenders and most obviously the negative terminal. if you don't get 12V everywhere, something isn't grounded correctly. Or your starter doesn't have power/ground. This would esplain why you get nothing by bypassing the solenoid