• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Replacing the electronic ignition with points - 1977 400 4V

Blue Brick

Well-Known Member
Local time
3:37 AM
Joined
Jan 12, 2024
Messages
61
Reaction score
6
Location
Arizona
I haven’t had any success diagnosing the issues with my electronic ignition, so I'm considering reverting to a points-style distributor.

What are the steps involved in making that switch?
 
Last edited:
To provide help, we will need to know a lot more... what car you have car, what engine, who's electronic ignition system and what you have tried so far. voltage measurements if you have them and... has it ever run properly and if answer is yes, what has been done or changed since then.
 
I haven’t had any success diagnosing the issues with my electronic ignition, so I'm considering reverting to a points-style distributor.

What are the steps involved in making that switch?
Not to bad really. Take the elct harness off, Ensure the IGN wires w 1 and 2 wires work, then 12VDC to the pos side of the coil and the ground lead from the dist to the neg side of the coil. Ballast resistor should be.5=-.6 warm.

1753963874427.png
 
Not to bad really. Take the elct harness off, Ensure the IGN wires w 1 and 2 wires work, then 12VDC to the pos side of the coil and the ground lead from the dist to the neg side of the coil. Ballast resistor should be.5=-.6 warm.

View attachment 1893862
Thank you for the diagram. This is what my current wiring looks like.(Yes I know it needs to be replaced, but it is holding current.)

Do I need to add a ballast with four terminals? Currently if the control module is not plugged in the coil gets essentially full voltage.

IMG20250601152157.jpg
 
Need to know what electronic ignition system you have. Mopar (orange, blue, black box) or some other brand. You stated "Currently if the control module is not plugged in the coil gets essentially full voltage." Does this mean that you have already converted to a points distributor ?
 
Need to know what electronic ignition system you have. Mopar (orange, blue, black box) or some other brand. You stated "Currently if the control module is not plugged in the coil gets essentially full voltage." Does this mean that you have already converted to a points distributor ?
No. Originally the car was set up with Lean Burn. The previous owner added a control module, a Mopar performance distributor, and changed the carburetor.
 
Understand that a POINTS ignition system, as the diagram Halifaxshops posted previously is different than an electronic ignition system as illustrated in the link I sent earlier showing how the Mopar electronic system works.
In a points system, battery voltage comes from ignition key switch. It is fed to one side of the ballast resistor. in the "cranking" position, the ignition switch electrically bypasses the resistor to feed full battery voltage to one side of the coil. I the "run" position, the resistor is in series with the ignition switch 12 V. and coil feeding a slightly lower voltage to the coil. The other terminal of the coil goes to the points in a "points distributor" to complete the circuit to ground. The cam in the distributor opens and closes the points turning the voltage to the coil on and off. Points closed energizes the coil, points open de-energizes the coil and creates the spark that gets steered to the proper spark plugs via the rotor in distributor cap.
( see link provided ) In an electronic ignition system, battery voltage comes from ignition key switch similar to above.. Battery voltage is fed to one side of the ballast resistor, AND the blue wire to the control module as well. The other side of the resistor feeds the + terminal of the coil on the black wire. In the "cranking" position, the ignition switch electrically bypasses the ballast resistor to feed full battery voltage to the coil. I the "run" position, the resistor is now electrically in series with the ignition switch 12 V feeding a slightly reduced voltage to the coil. The distributor in an electronic system does not have points. Instead it has a magnet and reluctor coil that sends small electrical trigger pulses to the control module as the distributor shaft rotates a star wheel past the reluctor's gap. The control module electronically switches the other side of the coil to ground completing the circuit. Switching action is similar in concept to points opening and closing, but accomplished electronically by the control module ( orange box) and not physically as points do. When commanded by pulse created by the reluctor, the control module electronically completes circuit to ground to energize the coil. When coil de-energizes as the control module turns off the voltage to the coil, the spark is created and steered by rotor in the distributor to the proper spark plug. The distributors for both systems described system is NOT the same. You indicated that : "The previous owner added a control module, a Mopar performance distributor," So yes.. you need to have the control module working if you have the distributor you say you have.
 
Based on what you say you need the control module hooked up. This previous post and various comments may help get it going.
orange box and small conversion harness QUESTION

Given the current wiring setup, I am unclear what modifications are needed to properly use a points-style distributor.

I understand that the wire from the points distributor connects to the negative terminal of the coil, which is straightforward.

My main concern is how to integrate the ballast resistor.
 
There are very simple wiring diagrams for Chrysler electronic ignition searchable on the net.
 
Bottom line is that If you want to convert to a points type system, first thing you need to do is get a points type distributor that's correct for your engine size. That's not what you say you now have. From there, if you follow the previous thread posted by Halifaxshops, that's a basic wiring diagram for a points type system. You will need to know the coil you will be using to be sure you have the correct ohm value ballast resistor. The value is specific to the type of coil being used. Of course you will also need to reset your ignition timing as part of the process which in it self is a whole related but different topic.
If you have all the pieces for the existing Mopar electronic system, might be better to get it running with that system before doing the conversion. The electronic Mopar system was part of tens of thousands of cars built and is quite reliable assuming that all the involved components are correct and wired properly. The wiring diagram for the Mopar / Chrysler electronic ignition system you claim to have that was shown in the previous threads I had sent you a link for. Here's the link again that has the wiring diagrams for the Mopar / Chrysler electronic ignition system.
orange box and small conversion harness QUESTION
You did not say what color control module you have, is it orange, black or blue in color. Orange is typical for a Mopar electronic system. It's most helpful to have a wiring schematic for your specific car as it's important to have the wiring correct either way you decide to go.
 
or just get a stand-alone ignition and a new coil, run a line from the battery with a relay and tie into the power at ignition switch, no guess work, option.
 
Bottom line is that If you want to convert to a points type system, first thing you need to do is get a points type distributor that's correct for your engine size. That's not what you say you now have. From there, if you follow the previous thread posted by Halifaxshops, that's a basic wiring diagram for a points type system. You will need to know the coil you will be using to be sure you have the correct ohm value ballast resistor. The value is specific to the type of coil being used. Of course you will also need to reset your ignition timing as part of the process which in it self is a whole related but different topic.
If you have all the pieces for the existing Mopar electronic system, might be better to get it running with that system before doing the conversion. The electronic Mopar system was part of tens of thousands of cars built and is quite reliable assuming that all the involved components are correct and wired properly. The wiring diagram for the Mopar / Chrysler electronic ignition system you claim to have that was shown in the previous threads I had sent you a link for. Here's the link again that has the wiring diagrams for the Mopar / Chrysler electronic ignition system.
orange box and small conversion harness QUESTION
You did not say what color control module you have, is it orange, black or blue in color. Orange is typical for a Mopar electronic system. It's most helpful to have a wiring schematic for your specific car as it's important to have the wiring correct either way you decide to go.

It's Blue, but it also had Chrome.
 
I haven’t had any success diagnosing the issues with my electronic ignition, so I'm considering reverting to a points-style distributor.

What are the steps involved in making that switch?
Very good move for reasons not yet obvious . Points cars are the only ones that will be running after an EMP strike. I know I sound crazy but you will find out over the next year. No negative comments please.
 
Very good move for reasons not yet obvious . Points cars are the only ones that will be running after an EMP strike. I know I sound crazy but you will find out over the next year. No negative comments please.
If you store your car that has electronic ignition with the battery disconnected. Will it still be effected by an EMP? Just wondering.
 
Auto Transport Service
Back
Top