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Ignition woes on my 1970 Dodge Dart with Pertronix ignition
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Author:  Beitie [ Tue Sep 09, 2025 4:32 pm ]
Post subject:  Ignition woes on my 1970 Dodge Dart with Pertronix ignition
Yesterday I received a call from my Dad. He was moving my car out of the way so he could get to his when suddenly the car died on him and would not restart. After I finished work, I drove over and we started looking at the car, trying to figure out what happened. We could not find spark making it to the plugs. At this point, the car had run for the past three years with a Pertronix Electronic Ignition system installed. I have probably driven the car about 2,000 miles with the system installed.

The first time we attempted to diagnose things, I did not have a proper multimeter along with me. Though I did have a test light. I could tell we had voltage to the positive side of the coil, and I could tell the ground was active as well (engine not cranking). When we cranked the engine over, I could see the test light pulsing with the test light on the negative side of the coil.

Video found here: https://youtube.com/shorts/wCNCOlObx4w?feature=share

So at the time, we suspected the coil had died. I took the coil to the local parts store, and we tested it with a multimeter there. The coil seemed fine. 1.8 ohms on the primary coil, and around 10k Ohms on the secondary side. No obvious leaks or visible issues.

Today I went back with a proper multimeter and did more tests. At the positive coil post, with the ignition on, and multimeter grounded directly to the battery I was only finding 10.12 volts. Battery voltage post to post measured at 12.49 volts.

I did not install the Pertronix system myself, so I looked around a little more. I found where the ballast resistor had been removed, and the connectors had been jumped together. Looks like a fine method to me.
Attachment:
File comment: Ballast Resistor Jumper
Ballast Resistor Jumper.jpg
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Checking voltage with my multimeter from connector to connector of those wires showed 11.77 volts. So seems like I'm dropping quite a bit of voltage from this connector to the coil.
Attachment:
File comment: Ballast connector voltage
Ballast connector voltage.jpg
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While working on all of this, a garage neighbor brought over his inline spark tester light. I can see the light pulse, but the pulse is very very weak.
https://youtu.be/-svYgqfrKWQ

I currently plan on putting in a new Pertronix system. I think I should also look into replacing the wire from the removed ballast down to the coil. Does anyone know where I can find connectors that look factory original? Specifically, if I could find the little black plastic part that goes over the connector where the Ballast used to be? Does anyone know what wire gage is used for this? Or where I can find a roll of a similar dark blue wire?

Any other thoughts or suggestions are appreciated as well.
Author:  MadScientistMatt [ Tue Sep 09, 2025 5:38 pm ]
Post subject:  Re: Ignition woes on my 1970 Dodge Dart with Pertronix ignition
If that's an Ignitor 1, you need the ballast in place or you can cook it. Do you have a set of points you can try as a back-up?
Author:  Beitie [ Tue Sep 09, 2025 5:44 pm ]
Post subject:  Re: Ignition woes on my 1970 Dodge Dart with Pertronix ignition
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Um, not according to their instillation instructions.
Author:  mr.norm [ Wed Sep 10, 2025 9:37 am ]
Post subject:  Re: Ignition woes on my 1970 Dodge Dart with Pertronix ignition
I have the ballast bypassed on mine too. As per the instructions. I have 46,000 miles on mine with not a problem. I did use their coil as well.
Author:  mcnoople [ Wed Sep 10, 2025 11:38 am ]
Post subject:  Re: Ignition woes on my 1970 Dodge Dart with Pertronix ignition
Quote:
Or where I can find a roll of a similar dark blue wire?

Any other thoughts or suggestions are appreciated as well.
You can get a decent selection of wire from amazon. An online vendor I have used in the past (with decent results) is waytek wire. I suspect the factory used 16 or 18 gauge wire for the coil, I would go 14 if I was replacing it. When searching online you need to look for heat resistant wire commonly labled with terms like "crosslinked." Off the top of my head I don't recall the differences between TXL/SXL/etc wire types but I recall that waytek gives specs on their site.

I know that you can purchased high flexibility high temp silicone insulated wire on amazon in small quantities suitable for a coil wire for a reasonable price.

As recently as 2015 chrysler was still using underspec wire in the engine compartments. I have seen 2005 era caravans with injector wiring melted together after the insulation failed AND 2014 era durangos with melted MDS solenoid wires due to underspec heat resistance. TLDR don't use "general" wire in an engine compartment or else you may have some weird issues show up later.

did a quickie look at waytek, this explains wire types....

https://www.waytekwire.com/catalog/wire ... 3a00ff1de3
Author:  Rick Covalt [ Wed Sep 10, 2025 12:28 pm ]
Post subject:  Re: Ignition woes on my 1970 Dodge Dart with Pertronix ignition
Problem with Waytek is that it looks like you have to buy 500' minimum.
Author:  mcnoople [ Wed Sep 10, 2025 2:02 pm ]
Post subject:  Re: Ignition woes on my 1970 Dodge Dart with Pertronix ignition
Quote:
Problem with Waytek is that it looks like you have to buy 500' minimum.
On wire yes, on other items not so much. I suspect that some sizes/colors/types are available in smaller quanities due to spool waste, but shipping would make it cost prohibitive.

I've bought some cooper bussman fuse/relay boxes from them and some adhesive lined heat shrink from them with no minimum order size. But I mainly listed it for the descriptions of the wire types. 10 years ago they were a very good source of GM metri-pak/weather terminals. These days the terminals are a little more widely available.
Author:  MadScientistMatt [ Wed Sep 10, 2025 5:57 pm ]
Post subject:  Re: Ignition woes on my 1970 Dodge Dart with Pertronix ignition
OK, I installed mine a long time ago and may be misremembering the instructions. Or maybe they've changed to a note about coil resistance instead.
Author:  Dart270 [ Thu Sep 11, 2025 6:24 am ]
Post subject:  Re: Ignition woes on my 1970 Dodge Dart with Pertronix ignition
I just looked at the package I bought (P-I) for a backup dist I just built a few months ago. It says minimum 3.0 Ohms for 1 to 6 cylinder engines, and to run a ballast if your coil primary has less than 3.0 Ohms. It also says maximum of 4.0 Ohms.

It does also say that leaving the ign on for extended periods can burn out the Pertronix unit. Same with points (if they happen to end up closed).

Lou
Author:  Greg Ondayko [ Thu Sep 11, 2025 6:25 pm ]
Post subject:  Re: Ignition woes on my 1970 Dodge Dart with Pertronix ignition
A thought to share:

I had the same issue in September 2020 with my '64 Dart on the day I was going to drive ~6 Hours to VA for an Auto X weekend.

I found it to be loose / corroded / high resistance Bulkhead/ Firewall Packard connectors.

Unplug all 3 Engine compartment firewall connectors and clean then re plug your terminals to the firewall bulkhead. This is common on old A bodes and can show up randomly as other things will not work correctly and or "Fail"

I have also had the same issue at times on my ' 69 Dart.


est of luck, and I doubt it is the pertronix.

Greg
Author:  Beitie [ Thu Sep 11, 2025 6:31 pm ]
Post subject:  Re: Ignition woes on my 1970 Dodge Dart with Pertronix ignition
Thanks much for the responses everyone. It's much appreciated.

I got a good start on the project today, and removed the old Pertronix kit. I may have messed up when I ordered that kit, now I'm fairly confident that it was the Ignitor I system with a 1.5 Ohm coil. I also found the distributor rotor had some damage. Not quite sure how that all happened, but since I'm the one installing it this time, I'm hoping to take a bit more care on it.
Attachment:
Damaged rotor.jpg
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There is one last roll in on Saturday evening in my home town, I sure hope I can drive this car there.
Author:  Beitie [ Thu Sep 11, 2025 6:38 pm ]
Post subject:  Re: Ignition woes on my 1970 Dodge Dart with Pertronix ignition
Quote:
A thought to share:

I had the same issue in September 2020 with my '64 Dart on the day I was going to drive ~6 Hours to VA for an Auto X weekend.

I found it to be loose / corroded / high resistance Bulkhead/ Firewall Packard connectors.

Unplug all 3 Engine compartment firewall connectors and clean then re plug your terminals to the firewall bulkhead. This is common on old A bodes and can show up randomly as other things will not work correctly and or "Fail"

I have also had the same issue at times on my ' 69 Dart.


est of luck, and I doubt it is the pertronix.

Greg
That's a good idea too. I've also found that I currently only have a ground cable going to my engine block, and not to the chassis. I plan on fixing that this weekend as well, and adding a ground directly from battery to body.
Author:  Greg Ondayko [ Fri Sep 12, 2025 2:29 am ]
Post subject:  Re: Ignition woes on my 1970 Dodge Dart with Pertronix ignition
Most cars if not all have a ground from the spare bolt hole near the have cover on the head to the firewall. Just add this and you should be fine as well.
Author:  Beitie [ Fri Sep 12, 2025 9:39 pm ]
Post subject:  Re: Ignition woes on my 1970 Dodge Dart with Pertronix ignition
I started working on everything on Thursday the 11th. But that went pretty bad. After removing the old system, I made a mistake of installing the ring terminals on the Ignitor wiring before installing the module into the distributor. Ooops. That lead me to attempt to go buy some new terminals from NAPA, but while doing that, I found I had forgotten my wallet at work. So I came back to the garage empty handed, only to realize I locked my keys in the garage. Ugh.

I came back to take the project on again today (Friday the 12th), and finished all the work. I felt good about the gap between the rotor and the module. I added a ground between the battery and the chassis, and I cleaned up some of the wiring a little to make it look a bit cleaner.

Once I was ready to attempt to start, I hit the key, and it was idling instantly.
https://youtu.be/hiKrSo_0Jsg
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