Mystery loss of electrics

[70spider]

Hello,
Ok here is the run down. Yesterday everything was going fine then all of a sudden I lose power and the car dies. It cranks but a weird thing happens I have electrics for about a second or two and I hear what sounds like a relay switching behind the dash click then everything cuts out. I have an electric fuel pump so no electrics no go. I repeat it and the same thing, power click no power. Could it be the ignition switch? No fuses blow. If I turn the key back to the off position and try again it repeats. It acts like a circuit breaker, pops then resets with no power. Mystery.
I'll study the wiring diagram to see if there are any factory relays there. Well at least I got about 200 miles out of him before he broke down again, making progress.

[70spider]

Update:
The click I hear is the gauge. So I tested the wires for power and there no power to the coil yet I have 12V at the alternator and the starter. From older posts on ignition switches it seems to be pointing me in that direction.

[markintheair]

Maybe you can check the brown wire going from the starter solenoid through the firewall. This wire goes through a white connector somewhere around the steering column area to the ignition switch. This is often a point of corrosion/malfunction. You can either take the wire apart and clean everything up properly, preferably removing the connector and making a new (better) connection between the two wires. Or you can run an extra #10 length of wire from the starter stud to the ignition and connect it to the #30 terminal. This takes a lot of load away from the ignition switch.