[hobgoblin351]

If you are still getting a draw whith all the fuses out, start checking the systems that have constant power. Ignition switch, horn ,hazards etc. It could be the harness, but if it visually looks good chances are its not bad and just grounding somewhere. I had this problem for a long time, and I did install a cutoff until I found it. How is the under hood harness, charred, dried out? Mine got mangled in a fire, replaced and I still and a draw on the battery. I finally tracked it down to a faulty horn switch, it was grounding to the steering colum. If you dont have one already get a wiring diagram. You can cross things off as you go along. You'd be surprised on what systems are wired together too! That a test light, and does your volt tester check for continuity? That comes in handy too. Take your time and keep track of what you've illiminated. There are only so many systems on an old mustang, you'll track it down. Just be glad it's not one of these new ones with 10,000 wires!