WIRING

Tommy, You need to take a hard look at your wiring and do any needed repairs and clean up at all connections including the muti pin rubber plugs in the wiring harness. The no spark issue is not related to a bad ground at the dash. The coil via the ballast resister gets 12V (hot) from the ignition switch. The ground on the coil would come off the engine block or out of the harness on the engine. Check for voltage at the coil with the ignition turned on. If nothing is there, work backwards. Here's a basic wiring diagram that you can follow.


Corrosion and loose connections are typical. The .250" "sta-con" quick connects on my 77 were all broken and may be what is falling off under your dash. I ended up replacing all of them as well as disconnecting every connection, cleaning and then putting it all back with a dab of dielectric grease. After a day of this, I actually picked up close to 2 volts of voltage drop to the dash just due to bad corroded connections.

You should have power at the red wire on the solenoid all the time. The white wire from the ignition switch to the solinoid is to energize the solinoid when to turn the key to start the engine.
You have said that the engine does turn over but check and clean up the battery cables at both ends.