So I removed dash to do heater core now car wont start. When I turn key to on position radio comes on but when I go to turn the car over it loses all power wont crank and radio shuts off. Gauge cluster is out of car currently. Auto car 1990 mustang gt. These plugs posted below are only plugs I'm seeing not plugged in and they are on left side of radio area. They are not for gauge cluster or headlights and stuff like that. Any help is much appreciated. Car has a megasquirt installed by previous owner.