I had a friend help me with a rewire job on my 70 Charger. It isn't working out so good though.
Before I get too far, a bit of a backstory...
Bob has a 71 Road Runner. 5 years ago he had an electrical snafu that almost led to a meltdown. After getting his car back home, he went through the wiring and replaced everything. After the changes, his car has performed like it should. 2 months ago I had trouble getting my Charger to start when I tried to leave a car show. I got the car started and drove it home, but I wasn't confident to drive the car much. Bob saw this as a great opportunity to help me rewire the car. Made sense to me. The wiring was almost entirely original and surely could benefit from an update.
Bob had the idea to use relays in a box to power up the ignition and headlights. The BATT + on the starter relay fed the power to those relays. We ran ONE 10 ga wire from the relays to the + side of the coil. Bob thought that the ballast resistor was UNnecessary for an electronic ignition, so the coil had full power. Things didn't make sense to me but I trusted what he was doing. The coil + terminal served as a junction to also connect the blue wire to both the Voltage Regulator and the blue ALT field terminal. The ECM plug was wired as per the MP ignition kit instructions MINUS the ballast.
Of COURSE it wouldn't start. We tried several times. ZERO spark coming from the coil wire.
I'd heard members here say to use the ballast and told Bob that we should, so he switched a few things around and we integrated one. Still no spark. The coil+ gets 11 volts, the coil- gets around 5. How can power get TO the coil but get nothing out?
The brown wire and blue wire are the run and crank. When the key is in the RUN position, I get power to BOTH wires. Is this right? It would seem to me that the RUN wire should be on, but the CRANK should only energize when the key is twisted to crank the starter....
Here is another really odd symptom: sometimes while cranking and getting no spark, when turning the key back to lock, it tries to fire. It did this before we disturbed anything. It did this with NO ballast. It does it with different ballasts. It doesn't do it every time, but it has done it with many different combinations.
Finally, yesterday while messing around with no clear idea of what I was doing, I spritzed ether down the carb and twisted the key. It fired up and ran like normal! I was so confused by this. I started it up at least 10 times after that with nothing more than a twist of the key and a light tap on the throttle. This morning it started fine. I tried again moments later and it failed to fire.
I appreciate any and all positive suggestions anyone can offer. I am grateful to Bob for trying to help out, but I think we bit off more than we can both chew on this one.

I am lucky in that I have a few other Mopars that I can test and swap parts.
I have already tried different coils, ECMs, ballast resistors...I even tried a different ignition switch. THAT was easy... just unplug the one from under the steering column and plug in another.

sounds like you Mickey Moused your system. Time to un-monkey it. Buy the factory harness and replace it. With Electronic Ing you still need a balast. Only when you swap to MSD or like system can you bypass it. The old system worked for 40+ years Why mess with it. Do you guys hack into the dash harness? That's not a cheap piece. I'd start by yanking the harness you all created, and get a factory unit. Then clean the bulkhead on both sides, re-wire the engine bay, clean all grounds, check your amp meter (if you like you can bypass that) and try and fire it up.

Seperate & check/clean the bulkhead terminals (wire brush for the male ones/spare male terminal for the female ones then spray with contact cleaner & blow dry em). Take off the yellow "ign" wire from the starter solenoid to avoid running the batt down (& no need for the noise distraction). It started so there's a loose/poor connection somewhere (check em all) & it's very likely wired right if power goes thru the ballast in ign1(run). You have fire at the coil primary & the ECU needs to open the coil neg pri circuit to fire the coil and the dist pickup triggers the ECU to do that. In "crank" (ign2) the brown wire circuit; the "point" of the ECU pentastar connector and the coil positive primary need fire (assuming 4 pin ECU/2 terminal ballast). In "run" same thing; the (ign1) blue wire circuit the "point" of the ECU pentasstar and the coil positive primary terminal need fire & as you know it goes to/thru the ballast first before it gets to the coil positive primary. Check ECU ground. Your VOM is your friend along with a helper (Bob!) to hold the key to start for your ign2 "crank" circuit tests. EDIT Check the reluctor gap & start unplugging/replugging connectors/checking tightness/clean connections etc & work your way toward the coil/ECU. Holler how it goes

Your clue is the coil negative (-) has 5-volts.
With the ignition on, engine not running, the ECU should be grounding the negative coil side, so it should be less than 1 volt. It looks like the ECU is not grounded. The case needs to have a good ground path to the engine block.

OEM is fine...As long as you recognize its limitations...

Once you stray from factory, might want to research how hard you're going to tax the system...

I've got OEM wiring in a '71 Body...

All connections clean, tight, liberal use of di-electric grease, properly grounded...

Lotsa years of service, no issues...

The dash side of the harness is still original. I refuse to whack into it because I am aware of the replacement cost! We did have the ammeter bypassed but when the car wouldn't start, we began to backtrack to search for the problem. I intend to have the guages refaced and have the ALT guage replaced with a Voltmeter.

"Here is another really odd symptom: sometimes while cranking and getting no spark, when turning the key back to lock, it tries to fire. It did this before we disturbed anything"

Hard to tell with all the other changes/etc. - but "sometimes" this is a symptom of a boogered/failing ignition switch. I'd check that carefully and perhaps replace it - could be worn out.

If it was me, I'd disconnect the battery cables completely until you replace with the new wires - it would suck to have a fire when your not there to see it and use your fire extinguisher...

Funny thing, I diagnose your problems as all starting from a bad ignition switch. When you turn the key to start, the ignition is fed around the ballast resistor. If the car cranks and doesn't fire, but tries to when the swithch is turned back to "run", that's your issue.

Using a stock ignition module, a few things have to be right:
1. Distributor should be grounded.
2. Ignition box must be grounded.
3. Ignition coil must be grounded.

During running, the positive terminal of the coil gets 12 volts through the ballast resistor which usually knocks it down to 8-9 volts. The negative terminal of the coil is grounded through the ignition box. Thus current charges the coil. When the points open or the magnetic pickup sends a signal to the box, the flow of electricity through the coil is interrupted and the magnetic field breaks down, causing current to flow out of the coil secondary winding, to the distributor and finally to spark plugs. To complete this circuit the coil must be grounded. If you're seeing voltage at the coil negative terminal, the ignition box isn't grounded well enough.

It's easy for others to tell you when you or a friend has screwed up, but it seems to me that you guys were almost there, just a few mistaken ideas.

When you install your new "factory" wiring, be sure to check the bulkhead connector because it's a possibility that the connector from your ignition switch "start" wire is damaged, which would explain why the differrent ignition switch didn't help.

I hope to never use a ballast resistor again. Every build I do uses a solid state CDI, I am using a MSA-6 on my '64Dog and the Accel 300+ on two others. There, instead of 8 volts or whatever charging the coil, I have 450 volts or so charging the coil. I don't think the chances of ignition box failure are worse for either the stock box or a reputable aftermarket box, I've never had one go bad. There is a question about the orange box on the '64Dog but that's inactive at present.

Feeding headlights and other big amp loads with relays is a good idea, too

R.

All these suggestions are excellent. I'm going out to the car in a few minutes and will report back with any and all results. Thanks to all!

that pertronix points conversion with flamethrower coil is sounding better and better..NO?

this is the very reason I ditch the stock ecu elect anything crap on my junk. been right where you are to many times to do it any other way now. they get the pertronix fix..and on a points car with points conversion they are a huge improvment of stock points.

I will not I know the beatdown feeling all to well working on SOMETHING THAT IS NOT BROKE TILL IT IS BROKE!...

Okay, here goes:
I went back to the car and continued to poke around. I pulled the 3 engine side bulkhead plugs to make sure all of the spades were pulled through enough. They all were. I pulled the bulkhead back into the underdash area to make sure that all the wires were pressed deep enough into the master plug. They were. Every connection in the harness was checked for correct fit. THEN I took the tester to it all again. I checked my findings against a 72 Duster with electronic ignition, a 75 Power Wagon, a 78 Trail Duster and a 67 Dart. All of them showed between 4.0 to 7.0 to coil+ at run. The coil- was always near 1.0 in those 3 cars and the Charger. The numbers made me think that the coil and ECU were getting power in as they should. I was pissed, so I walked away.
Moments later as I was kicking back, it occured to me. The only reason that a properly functioning coil should get power IN but not OUT is because it isn't receiving a proper signal from the distributor! I plugged in a spare factory electronic distributor and the car instantly fired up! The reluctor gap was set correctly. The wires were in great condition. I think that the pickup simply crapped out. I swapped in a reluctor and pickup from another spare and was just about to put it in when a friend came over. After he left, it was dinner time. I'll finish tomorrow.
Bob's wiring actually worked. The cars other wiring was fine too. The coil, ECU, ballast resistor and Voltage Regulator all were fine. The distributor was part of a Mopar Performance conversion kit I bought in 2001. I've had the No-Spark problem on occasion with this distributor in the past. I'd just junk it but it was curved to a maximum of 14 total degrees. I run 17 initial and 31 degrees total. Any less than 17 at idle and it runs choppy and lazy. Any more than 31 and it rattles like marbles in a soda can.
Thanks to all!

Again, make sure the ECU is grounded good or you could fry the pickup in the new dist. If the ECU has a bad or weak ground, it will try to ground itself through the dist pickup. Also, because the ECU is looking for signal from the pickup and referencing it to the engine ground, the ECU should have a ground to the engine block it avoid "ground loop" issues where you end up with two different "ground" reference points. It sounds like your friend knows what he is doing, so mention this to him.

Problem solved/you had an extra pickup nearby/Bob's off the hook. All is good in the 'hood. That wasn't too bad now was it

Having you guys to help is great. The electrical system is my weakest point and I appreciate every suggestion.