Refresher on Orange box 3 wire conversion - 12V conversion

[Mike McGuire]

Hello Mopar Enthusiasts!

I'm attempting to wire the ignition for my current project, the 1955 300 clone, and could use a mental realignment on which wires go where.
I'm going with what I'm familiar with, something similar to a 1968 Newport ignition, but not with points, rather an Orange Box.
I've swapped out the points distributor with an aftermarket from hot hemi heads, and it is time to install the orange box.
My previous orange box swap was with a 4 wire harness. This one only has 3.

They are: Green (with red stripe), Blue (with white stripe), and Black (with yellow stripe).
From Mancini Racing:
blue - ignition 1 (is this usually at 1 side of the ballast resistor?)
black - ties to coil - negative
green - do not connect

google AI has something completely different, leaning towards Mancini advice, but thought the collective body of knowledge might be able to help straighten me out.

Advice appreciated. Happy Moparing.
Mike

 

[Vaanth]

Hello Mopar Enthusiasts!

I'm attempting to wire the ignition for my current project, the 1955 300 clone, and could use a mental realignment on which wires go where.
I'm going with what I'm familiar with, something similar to a 1968 Newport ignition, but not with points, rather an Orange Box.
I've swapped out the points distributor with an aftermarket from hot hemi heads, and it is time to install the orange box.
My previous orange box swap was with a 4 wire harness. This one only has 3.

They are: Green (with red stripe), Blue (with white stripe), and Black (with yellow stripe).
From Mancini Racing:
blue - ignition 1 (is this usually at 1 side of the ballast resistor?)
black - ties to coil - negative
green - do not connect

google AI has something completely different, leaning towards Mancini advice, but thought the collective body of knowledge might be able to help straighten me out.

Advice appreciated. Happy Moparing.
Mike

Although there are some wire color variations in production cars and trucks, the general color coding of the wiring, and that used in the original Chrysler wiring harness kit, Chrysler P3690152 is as follows:

1. Connection to Ignition Run circuit - blue with yellow tracer
2. Connection to ignition coil negative (-) terminal - black with yellow tracer
3. Connection not used with 2-terminal ballast resistor and 4-pin ECU - green with red tracer
4. Connection to distributor pickup coil 1/2 - grey, may have a black tracer
5. Connection to distributor pickup coil 2/2 - black or brown with white tracer


4-pin ECU and single 2-terminal ballast resistor wiring:

 

[Lefty71]

How " different" is your wiring from stock on the vehicle itself?? Maybe a diagram will help? I dont see one for 1955 on Mymopar.com, but 1956 chryslers are there.

 

[Mike McGuire]

How " different" is your wiring from stock on the vehicle itself?? Maybe a diagram will help? I dont see one for 1955 on Mymopar.com, but 1956 chryslers are there.

I'm calling 'wiring' different from 'ignition'. For 'wiring', I'm going with a kwik wire kit since all bulbs and items are 6V. the wires are meh and the insulation is worse (being a 70 year old car). My goal its to get it running and wrench on more correct methods during the off season. (similar to not wanting to work on your snowmobile during the winter months). I'm creating a 68 Newport ignition, without the points. (Will be using an electronic voltage regulator, instead of the factory one, as I understand the stock ones are more susceptible to transients created with the aftermarket ignition/(orange box)). Trick is the 3 wire harness & orange box I found in my mountain of spare parts.

 

[Mike McGuire]

Although there are some wire color variations in production cars and trucks, the general color coding of the wiring, and that used in the original Chrysler wiring harness kit, Chrysler P3690152 is as follows:

1. Connection to Ignition Run circuit - blue with yellow tracer
2. Connection to ignition coil negative (-) terminal - black with yellow tracer
3. Connection not used with 2-terminal ballast resistor and 4-pin ECU - green with red tracer
4. Connection to distributor pickup coil 1/2 - grey, may have a black tracer
5. Connection to distributor pickup coil 2/2 - black or brown with white tracer


4-pin ECU and single 2-terminal ballast resistor wiring:
View attachment 732627

Thanks for this Vaanth, appreciate this. I may just get a new 4 wire harness & box, instead of finding the correct way to wire the 3 wire harness with the one I bought previously (a few years back). This diagram is fine, but the wires to the distributor, are not part of the provided subject box/harness. I'm wondering without the distributor wiring to the ignition box.... how the coil would receive the trigger signal to fire, without the distributor connected to the ignition... Maybe there is away to wire around it..? Not wanting to go too far down the wrong rabbit hole, it might just be easiest to go with the 4 wire set up... & start the beast.

 

[Big_John]

Thanks for this Vaanth, appreciate this. I may just get a new 4 wire harness & box, instead of finding the correct way to wire the 3 wire harness with the one I bought previously (a few years back). This diagram is fine, but the wires to the distributor, are not part of the provided subject box/harness. I'm wondering without the distributor wiring to the ignition box.... how the coil would receive the trigger signal to fire, without the distributor connected to the ignition... Maybe there is away to wire around it..? Not wanting to go too far down the wrong rabbit hole, it might just be easiest to go with the 4 wire set up... & start the beast.

By "4 wire" do you mean the dual ballast resistor 5 pin ECU and "3 wire" is for the 4 pin ECU?

Most of the newer ECUs I've seen are 4 pins with a single ballast resistor. I even have read the 5th pin in some of the new replacements are dummies to keep people from returning them, but that could be just rumor too.

That said, the 4 pin ECU is easier to wire, uses a single ballast resistor.

BUT!! The question to ask is what you are using for a distributor?? If that's a true clone with an early Hemi, I'm not sure if there's a later distributor that would work without some work. I may be completely wrong on that, but I do know you need to use the distributor for the electronic ignition.

If you are using an early Hemi, you can use a Pertronix (I suggest the II model) if you have a correct dual point for that Hemi and forget about the Mopar electronic ignition. That would be a lot easier to wire too.

 

[Mike McGuire]

By "4 wire" do you mean the dual ballast resistor 5 pin ECU and "3 wire" is for the 4 pin ECU?

Most of the newer ECUs I've seen are 4 pins with a single ballast resistor. I even have read the 5th pin in some of the new replacements are dummies to keep people from returning them, but that could be just rumor too.

That said, the 4 pin ECU is easier to wire, uses a single ballast resistor.

BUT!! The question to ask is what you are using for a distributor?? If that's a true clone with an early Hemi, I'm not sure if there's a later distributor that would work without some work. I may be completely wrong on that, but I do know you need to use the distributor for the electronic ignition.

If you are using an early Hemi, you can use a Pertronix (I suggest the II model) if you have a correct dual point for that Hemi and forget about the Mopar electronic ignition. That would be a lot easier to wire too.

Thanks Big John,
What I mean by "4 wire" is 4 useful wires, the 5th wire is NC or not connected.

The distributor... It is not a true clone. I'd like to avoid the points, so Hot heads sold me a whole kit (5 + years back during covid. I just called them and they were very helpful.). The distributor is a small block distributor, for use with Chrysler electronic ignition. There is a distributor extender I had to use that got me the correct depth. somehow somewhere along the way the orange box and harness vanished, either into a Newport or just vaporized. The only remaining one in my stock pile is the subject module with a 3 wire harness & plug combo. I'm going to give up on that and just get a plug/ 4-wire (or 5) harness & box from a local parts store...

Appreciate the brain on this. Mike

 

[Mike McGuire]

The wiring and diagram I posted is for the Mopar Performance/Direct Connection wiring, and essentially a stock style wiring for a two terminal ballast resistor and stock type distributor with the magnetic pickup.

Without the wiring from the ECU to the distributor, which must have a compatible magnetic pickup, the distributor cannot trigger the ECU. The wiring setup you have sounds like it is for something else, and perhaps the distributor as well. Because you are using the "orange box" ECU, I assumed a compatible distributor. Looking at Hot Hemi Heads, it looks like they sell Mallory Unilites and MSD distributors. These are not usually for use with a Chrysler ECU.

If you are using a Mallory three wire distributor, it is wired like the following image shows:
View attachment 732649

But, I am guessing here now without knowing what you actually have.

Thanks Gary, I just called hot heads and they have my buying history and confirmed I got the whole enchilada 5 or so years back, including the small block distributor, distributor extender, Chrysler orange box and 5 wire harness ( I loosely refer to this as a 4 wire harness as 1 wire is not connected).. The ignition box provided is gone, but I had this other one with the 3 wire harness in stock, so this was my motivation, to use something I already bought. I'll have to take a closer look at the O.B. but think the easiest most reliable move I can make right now is to just get a 5 wire harness and connect it similar to the way your first diagram detailed. Current shot of project included.