73 Duster only starts in "run" not start posistion

hey thanks guys I have been away for a while. I have been driving my car for a while and havent had time ti test any of this because it just decided to run. Yes my ECU is grounded very well i chipped paint and even double grounded it with a test wire once. Pretty much i started undoing my wiring harness and unwrapping the electric tape to inspect wires.

then I undid the coil made sure it was properly hooked up and grounded and just for grins I put in the old box to my surprise it fired right up no problem.

I have just left it and driven it like this for a week when a few days ago i decided to wrap up my wires again (worrying in the back of my mind I might screw it up) surprise surprise it wouldn't start. so I decided to tackle it again. I went and got a voltmeter undid my pos coil side while cranking...nothing. HA then I realized I have the com ground on the gauge unhooked. reattached it and tried again. I get 9.5v on start and 10.5 on run. so I hooked the wire up back to the coil and presto the car worked again. I DID NOTHING besides check voltage and it fixed it. The wires seem good but the way its acting leads me to believe something is wrong with the wiring since it fixes itself