It sounds like you have a short somewhere.
One thing you should do as general rule to pinpoint a short is to test any suspect wire leads with a Multimeter. My friend (who is far better with electronics than I) used a Multimeter to measure the resistance and continunity of several wire leads on my '66.
The first place I would begin checking for shorts would be the front parking lamps. I had a backup lamp that had to be unplugged because it blew a fuse every time I put it into reverse.
The next place I would check would be the wiring in the steering column. This is also a common place for shorts to occur.
You should go ahead and order the wiring manual for your car. If you plan on keeping it for any amount of time, you're gonna need it!
The things that you almost have to have when pinpointing problems like these are a Multimeter, wiring manual, a bucket of fuses, and a lot of patience.
Good luck!
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2000 GT --
Black, 5sp, Mach460, Bassani CatBack & X-Pipe, MAC Cold Air, 70mm Tbody, Hurst Shifter
1966 Mustang Coupe --
Tahoe Turquoise, Pony Int, A-Code, C4 Auto
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scott@pearland.com