Electronic Conversion Kit
- Thread starter nodemon
- Start date
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12/71 build date.. So, probably factory points car...and at some point a conversion was started on this car (distributor), but that's as far as it got.. I see no evidence of any mods to harness..
Professor Fate
Push the button, Max...
Okay, so it wasn't already electronic ignition, it just had an electronic distributor in it that wasn't connected to anything?
Then you just need to follow the instructions in your new conversion kit to get it wired up, or follow @Mattax 's nicely done instructions above (assuming it's a newer kit with a 2 connector ballast and not the older four connector ballast kit...).
Looks like he's saying it had an electronic distributor chunked in it, but nothing else had been done to convert it. So you'll need that harness I linked to. Easy peasy.
The kit came with the ignition module harness plug, so I'm good there, if that's what you're referring to. Someone on the thread mentioned to NOT use a 1.5 ohm ballast...but that's what my kit came with...Should I NOT use that one..??
Yeah it is. Cool Then you probably have it all. I'm pretty conservative, so I'd use that ballast. When it gets hot, it will probably be more like 1.0 or maybe even .8 ohms. What that means is, it will drop voltage to the ECU more than say a .5 ohm. Those can sometimes deliver too much voltage to the ecu and burn it up, so I always err on the side of caution. Besides, if it fires the ecu and plugs with a 1.5 ballast and it will, ain't that enough? Let the arguments ensue. LOL
In regard to the ballast resistor, the one that came with the kit will work fine.
There are a lot of really smart people on this website (not me) that have figured out how to optimize every detail for maximum performance on a great variety of things. This often leads to very detailed and specific advice. And it is usually good advice.
However, if you are just a run of the mill normal schmuck like me, you often just want to get your car running reasonably well so you can drive it. In this case some of the advice can be over the top for what you are working on, and may not be worth the extra effort or cost.
You kind of have to figure out for your self how far down any given rabbit hole you want to go. Unless you are a racer looking for every last horsepower, the point of diminishing returns happens often pretty early.
One of my friends used to say: poor people have poor ways….
There are a lot of really smart people on this website (not me) that have figured out how to optimize every detail for maximum performance on a great variety of things. This often leads to very detailed and specific advice. And it is usually good advice.
However, if you are just a run of the mill normal schmuck like me, you often just want to get your car running reasonably well so you can drive it. In this case some of the advice can be over the top for what you are working on, and may not be worth the extra effort or cost.
You kind of have to figure out for your self how far down any given rabbit hole you want to go. Unless you are a racer looking for every last horsepower, the point of diminishing returns happens often pretty early.
One of my friends used to say: poor people have poor ways….
Shouldn't the coil primary resistance be taken into consideration when selecting a ballast resistor?
Here's a question I asked Rick Ehrenberg about the conversion kit I bought from him...
"Would it be a safe assumption that the resistor value plus the primary resistance value would be about 2.0 to 2.5 ohms allowing a mix and match of coils and resistors adding up to that....Or am I way off base?"
His answer was.........
"Your math is absolutely correct!
Rick"
Sorry, one more thing to think about.....Maybe time to switch to an HEI system
Yes, I just want to finally drive the damn car...lol
Almost 4 years and it's never been started, let alone driven since I bought it.
I know so many here are trying to help, but unfortunately, a lot of their great advice does just go way over my head and skill set. I could delve deep and learn more, but yeah, I just want to DRIVE..
The coil resistance and ballast resistor values are listed in factory shop manuals for the electronic ignition years. Looked them up once, but don’t remember the exact values
What I'm saying is, I'd rather be off with "too much" ballast, than "not enough". In other words, I'd rather be safe than sorry. Because sorry will happen at the least opportune time.Shouldn't the coil primary resistance be taken into consideration when selecting a ballast resistor?
Here's a question I asked Rick Ehrenberg about the conversion kit I bought from him...
"Would it be a safe assumption that the resistor value plus the primary resistance value would be about 2.0 to 2.5 ohms allowing a mix and match of coils and resistors adding up to that....Or am I way off base?"
His answer was.........
"Your math is absolutely correct!
Rick"
Sorry, one more thing to think about.....Maybe time to switch to an HEI system
Yes and they are higher than almost everyone's advice of .5 to about .8 ohms. The MP kit came with a 1.5 ohm resistor. That's what I prefer to use.
Picked one up at O'Reilly's..
The simple version is the combination of primary coil resistance and the ballast resistor will determine the current flow through the coil.
When the engine is at higher rpm, more current means faster the voltage and energy increaes on the secondary side. This is helpful because there is less time between sparks to reach voltage required and run a strong spark. At street speeds this is less an issue than racing rpms. This idea of a temperature adjustment was important enough that it was used by Chrysler and some other companies.
Resistance increases with temperature.
from 1969 Master Technicians Conference 259. p 5
1970 Points Ballast resistor checked at 70-80* F
1973
@67Dart273 or @KitCarlson can better discuss the effects of the coil saturation (energy build up in the secondary side) on the primary current flowing through.
With Chrysler's solid state igniution, the current through the coil also goes through the controlling leg of the ECU. A higher resistance ballast allows less current through and better protects that ECU circuit and as well as the coil.
When the engine is at higher rpm, more current means faster the voltage and energy increaes on the secondary side. This is helpful because there is less time between sparks to reach voltage required and run a strong spark. At street speeds this is less an issue than racing rpms. This idea of a temperature adjustment was important enough that it was used by Chrysler and some other companies.
Resistance increases with temperature.
from 1969 Master Technicians Conference 259. p 5
1970 Points Ballast resistor checked at 70-80* F
1973
@67Dart273 or @KitCarlson can better discuss the effects of the coil saturation (energy build up in the secondary side) on the primary current flowing through.
With Chrysler's solid state igniution, the current through the coil also goes through the controlling leg of the ECU. A higher resistance ballast allows less current through and better protects that ECU circuit and as well as the coil.
Last edited:
67Dart273
Well-Known Member
^^And that is the thing^^ None of the type of data that would allow comparative coils to be subbed was ever published by Chrysler, and no surprise there. Simple DC current and resistance does not tell the story. The inductance of a coil along with other circuit variables, for example, determines the time constant which affects the change in current flow and saturation when substituting coils. Even something like an extra long harness, AKA let's say you had an oddball deal like a stern drive in a quite long boat, and of course the key is way up front or on a flying bridge. The combined length of the power circuit (without a relay--and including (in a boat) the grounding wire, might just have enough inductance to change the circuit constants.
Frankly, I think about the best someone could do--and even this might be affected by such things as modern chinese replacement ECUS--is to gather up several example ECUs and hopefully, "known correct" mopar coils and ballasts, along with prospective modern replacement coils, and test them in some way that would detemine spark ENERGY along with monitoring average and peak current, and temperature of major components such as the coil, ballast, and ECU switching transistor.
Remember, guys, you are treading on untested ground with this stuff.
Frankly, I think about the best someone could do--and even this might be affected by such things as modern chinese replacement ECUS--is to gather up several example ECUs and hopefully, "known correct" mopar coils and ballasts, along with prospective modern replacement coils, and test them in some way that would detemine spark ENERGY along with monitoring average and peak current, and temperature of major components such as the coil, ballast, and ECU switching transistor.
Remember, guys, you are treading on untested ground with this stuff.
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