12v key on problem

Good evening everyone. I have recently installed a new motor in the duster. I also installed a complete MSD ignition. The problem is that when I crank the motor with the key. The 12v key on power disipates tho around 6v. Which will not fire the ignition. I put my voltmeter on everything that has 12v key on power and all of them the voltage drop’s. Anyone have any advice for me. I would greatly appreciated it. Thanks