Help! Sudden electrical problem

[Farmstore34]

Hey all'
I went to use my '72 k20 today, it has been working great, and stopped to throw some stuff in the back. When I got back in, I turned the key and there was nothing. I checked around, I had no lights, hazards, heater, radio, NOTHING. I tried roll-starting with no luck, then went and got another rig and jumper cables. Again, nothing. I towed it home, got my elec tester out, and the battery is fully charged. I have power down to the starter solenoid, but no power coming out of the solenoid on the other terminals. Would a bad starter/solenoid cause a no power condition on the rest of the system? I've haven't had any electrical problems since I got it a year ago. Thanks in advance,
Colby.
P.S. it has a 350 motor and 4-speed.