1972 Mk IV No crank

I drove my 72 Mk IV for about an hour then shut it off to look at another car. 5 minutes later I try to start but no crank no start from starter. Lights and blinkers work. I bench-checked the starter and solenoid is good. I replaced ignition switch at top of steering column. Still nothing. Replaced lock cylinder and still nothing. When I tried to turn key I can hear a slight clicking from the firewall. Cleaned all contacts, still nothing. I've gone over everything I can think of. Jumped solenoid on car and motor will turn over but won't start with key.