MSD 6AL ignition box

i had same problem on my 70 dart .while cranking i was not getting power where i should but with key on it seemed to be wired right .i tried a bunch of different ways and finally just ran a hot wire from the fuse box to a toggle switch on the dash . so now if somebody tries to steal it also it wont start unless they know aabout the switch and if you have to shut the motor down because of problems while driving just flip the switch and its dead but the key is on so youre steering doesnt lock. i think the problem with mine is the wiring harness is kinda butchered and needs to be replaced.good luck