I'm having vehicular electrical issues.?

My 1981 Chevy pickup wouldn't start yesterday. The battery was fine. I would turn the key and nothing. Not even a solenoid click. So I bought a new starter and put it in today. When I turned the key to "on", all my dash lights came on as usual. Then when I tried to start it, the solenoid would click and all power would disappear. No lights, no headlights, nothing. If I pull the battery cable off and then put it back on I get my lights back but the same senario plays out when I try to start it again. Any ideas?