Fuse Blows!

My 74 Dart Sport, which is cloned into the Duster in my avatar, just started blowing the fuse that handles the turn signals, back up lights, heater blower and the wipers. I only have the turn signals and back up lights on the car; the heater and wipers aren't on it.

The fuse blows a couple seconds after the key is turned on with neither the t/s or back up lights on.

So, this tells me that there is a dead short before or at the back up light switch, before or at the turn signal switch, or before where the wiper or heater switches were.

I have a wiring diagram and have begun to look at it. There is no legend with the diagram, but I'm sorta figuring it out.

This just occurred, and I want to take it to a show Saturday (It's NOT a show car, just want to take it!), so I thought maybe I could save some time by asking on here if there is anything that is a common issue. I can live without the back ups, but I'd like to have the turn signals.