HELP!!!Wiring issue with 73 Dart Sport

hi guys, So long story short. I replaced my alternator with a new one that has its own regulator. I also pulled out all wiring under my hood that was not connected and went no where. I was concerned about something catching on fire.
NOW.....
When I turn my key to start position, my MSD box looses power and car has no spark to start. Everything has power when key is in run position, but as soon as i turn it to start possition everything dies. I know this should happen, but the MSD still need power to spark. I wired in a push button so I can keep it in run possition and just jump power to trigger the starter but same thing happens. I wired it from battery to the button and back to starter relay. (Yellow wire)
Am I missing something simple here??