74 Duster Electric problems

You can get a multi-meter for free w/ coupon at Harbor Freight. I keep one in all my cars. The wiring diagrams are fairly simple and easy to read, and these cars are fairly simple wiring. The main thing that would be blowing all these fuses is short(s) to ground. If all your wires are frayed and crumbly, that could do it, but usually the interior wires are still fine (tail-lights, etc.). I would also suspect the fusebox. You can drop it down w/ one screw.