Sanity Check - I'm missing something simple....

[Marty73]

73 Challenger with a basic 318, all factory.

About a month ago it stalled and will not start. Since I've been having odd electrical issues I pulled the trigger on a new dash harness. Needed to be done regardless since the old one was molested and cracking and I had some other issues that just needed fixing...

Anyway- new engine bay harness, dash harness, rear harness. So damn near all the wiring is new. New coil, ballist, ignition module.

No spark...here is the sanity check part..

I should have 12v to the positive coil side right?

Could this be the ignition switch? It's only a couple years old, but was cheap?

What is the troubleshooting procedure for chasing spark? All my connections look good so i'm a little stumped

Thanks, I appreciate any suggestions

[Marty73]

Oh, should be noted that I had the issue prior to the dash harness swap (one of the reasons that made me pull the trigger on the new harness)

[Katfish]

Put this together while troubleshooting an issue I thought might be the ignition switch.
It's for a 70, but I think it will cover the Start/ACC/RUN circuits the same.
Ignore the text at bottom, it's for a GEN3 swap.

[Chryco Psycho]

Probably as simple as a ballast resistor , you should have 7v at the coil in run position & 13v while cranking

[JH27N0B]

I assume you verified no spark at ignition wires?
I've had a won't start situation on my 71 a few years ago, ran when parked, 6 months later crank no start, which turned out to be something with the reluctor in the distributor.  The guy managing the storage places friend was a retired mechanic and he figured it out.  I wasn't there but was told they replaced the reluctor and properly gapped the pickup to get it running.
Then I bought a Magnum with a 360 I wrestled with an intermittent no start problem on for 2 years.  Being electrically ignorant I threw parts at it like new ballast resistor and ECU.  A friend checked it out for me and said the reluctor was worn but gapped ok. A week later at a cruise it wouldn't start.  He was there and looked at it, he unplugged the pickup and plugged it back in, and then I tried it and it fired up.
I replaced the reluctor and pickup soon after and gapped it properly, the car has started fine ever since.  I'm knocking wood that I finally through the right parts at it and it won't leave me stranded at an event!

[Marty73]

Well, I'll double check my voltages and maybe replace the dist stuff. What's another 50$ at this point 

[Marty73]

I've already replaced the ballast, ignition module and coil. Forgot to mention that

[tparker]

I'm not the best one to speak on this topic, but I've had to fix various electrical issues on various cars. My recommendation is to test the system with  a volt meter and  check all connections and grounds. I typically will start working backwards. Is there spark at the plugs? Is the coil getting voltage? etc.  If it isn't  you  start working  backwards or you know it is the distribututor, coil, ballast resitor, or ECU or what not. I am sure there are a dozen entries on here that go over each of these components. I found some useful stuff at Dead Dodge Garage on YouTube, maybe this would help.

https://www.youtube.com/watch?v=7Re_L-OlEOo
https://www.youtube.com/watch?v=oTSxN1Kwfuk
https://www.youtube.com/watch?v=5QPUM-fRRSI