On Going no start

[22dog22]

Just a bit of the story, 69 Cuda, 318 auto, have installed Pertronix dist and the correct coil, have been tracking down issue of no start. Last item on list was to replace the coil to dist. cap spark plug wire [ did replace the whole set of plug wires, but coil wire need to be longer due to where I have the coil mounted], and unhooked the electric choke wire I had hood to the coil. The other day I was able to try to start the car again, it seemed like it wanted to fire while in the crank key position, but as some as you left the key god to run , it did not want to try to fire any longer [ TO NOTE THERE IS NO RESISTER BLOCK] so I think I have lost the run power going to the coil from the ignition switch, I think I need to install a relay to keep power [ 12 volts] going to the coil so the car will start. Since I do not have power that will stay on from the ignition switch , in the run position , where under the hood should I pick up 12 volt switched power source for the relay trip power?

 

[67Dart273]

Easy to check. Clip a test lamp or multimeter to coil + and ground, turn the key to "run". Should have power. Twist and hold the key to "start." Should have power.


First I was under the impression that Pertronix used a ballast.

But regardless here is how this works

There is only 1 switched 12V, from the key, coming into the engine bay, in the RUN position of the key. THIS GOES DEAD when the key is twisted to start. Often this is dark blu, "IGN1". This supplies loads such as ignition system, alternator field, voltage regulator, electric choke if used. IT IS NOT fused
AGAIN, it GOES DEAD when the key is twisted to start

During cranking, "start" there are TWO separate power sources into the engine bay, from separate contacts in the key. One is the normally yellow "start" wire which fires the start relay and the sater

The second, normally brown, is IGN2, the ballast "bypass" circuit. This connects to the coil + side of the ballast resistor. IF YOU DO NOT use a ballast, you MUST jumper the IGN1 "run" and the IGN2 "bypass" together at the power point for the ignition system, ALSO making certain, that you did not cut loose any of the other needed loads in the branch