69 Dart gts
 

Hi all,
I have a 69 dart auto that starts one out of ten times with the key after cranking it for a while and the other nine times it will start immediately by jumping the starter relay. But going with the key it just cranks and cranks. I’m really not good at investigating electrical problems but can follow along with a multi meter if the directions are explicit enuf. (Pictures…lol)

thanks in advance

Dose the car have a Single Ballast Resister or a Dual Ballast Resister?

It has a MSD ignition but looking at it, it appears to be unconnected on both side. I have no idea if the guy who put the MSD in if he did anything special to the ballast. Is there a set way or just pull off the clips on each side?

Not sure what your asking? (Is there a set way or just pull off the clips on each side?) But lets not get to far off the path...

What MSD unit is it? Should say on the cover (MSD 6A or MSD 6AL) ????

Lets get back to the fix.... Scene it starts with the key in the run position when you jump the start relay. I'm going to guess that the Ignition switch when in the crank position is not feeding power to the ignition system.
The reason it starts when you have the key on and jump the relay and it starts is because the 12 volts is present at the ignition unit.
The reason it only start 1 out of ten time, is because when you turn the ignition key to the cracking position and then you quickly let go of the key and it can snap back to the run position fast enough. That's when it will catch and start and stay running... So what need to be fixed (I assume) is the ignition feed that is related to the cranking/start position....
Are you with me?

Also... If it is one of these MSD's this may help for you to do some checking....
https://documents.holley.com/6425.pdf