What is this ?

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MikeD

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It's on the intake of my 76 400, there's also a 4 pin and a 2 pin ballast resistor on the car. Just trying to clear some junk off the firewall.

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The first pic, that is the resistor for the electric assist choke for the carb. The next two pics, it appears someone "piggy backed" a 4 pin resistor in with the two pin. Apparently it has been converted to electronic ignition? If so, it definitely shouldn't have been done that way.
 
Electric choke assist caused the choke to open faster satisfying EPA. That controller wasn't sealed so moisture and corrosion might have killed it long ago. If it does still work you may want to keep it in place.
Your 76 model came with electronic ignition and dual ballast resistor. No idea why the extra was added on.
 
You can use a 2 pin. The4 pin was used in ‘73+. Rpm m not really sure as to why.

Adding the electronic ignition should be as simple as the ignition box, ballast resistor, distributor and a wiring harness. 4 wire connection. 2 to the distributor, 1 to negative coil, 1 to ignition key on hot wire.
 
You only need the the 4-pin resistor when you are using a 5-pin ECU.
Someone probably added electronic ignition and didn't understand the system.


Alan
 
OR you can eliminate ALL the bulls**t and go with a modern ignition and coil that does not require a control box , ballast , harness and 4 to 2 to 1 connector . Simple !
 
there's 2 wires in each plug from the ignition but the wiring diagram shows only two wires.
Wiring diagram will show two ignition circuits from the key switch.
Ignition 1 is key in run postion. Power goes to a connector on the ballast resistor (usually a blue wire) then divides. Some goes through the ballast resistor to the coil, some to the voltage regulator (usually a blue or blue with white trace). So that connector on the ballast has two wires.
Ignition 2 gets power when key is in Start position. That's the brown wire. At the connector on the ballast resistor it joins with the wire to the coil.

The double ballast resistor above is something added. Those were used on factory electronic ignitions in the mid 70s. One resistor helps regulate current that runs the amplifier (ECU), the other regulates current to the coil. Newer '4pin' ECUs have internal regulation and don't need the second resistor. If the engine is running a points type distributor or magnetic pick up with a later ECU, then you only need to have one resistor. The resistance of the resisistor should be matched to the coil.
 
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If you made a schematic of the car's original power, ignition, and start circuits it will look something like this.
upload_2019-7-9_22-30-30.png


A '4 Pin' ECU can be wired in like this.
upload_2019-7-9_22-36-29.png

The terminal at the point of the pentagon connector is power supply.
Two wires connect to the magnetic pickup in the distribributor. They provide pulse signal.
The remaining pin is the coil to earth. Just like a points distributor it's connection to earth is closed and then opened.
The missing pin is where the second power wire was on 5 Pin ECUs.
1972 Imperial & Chrysler Ignition System Service Book (Session 292)
 
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On a practical side, crimping three wires on a terminal is not going to work well.
So you may find the ECU power wire tapped in at another location.
upload_2019-7-10_8-34-27.png

(Factory harnesses with electronic ignition usually have a splice tap starting around '72.)

Here's a general scheme of the 5 Pin ECU wiring.
upload_2019-7-10_8-41-51.png

ECU harness wire colors will vary.
(based on Fig 19-3 in the MP/DC Speed Secrets collection of bulletins)
 
Couple of questions,If I use the two pin ballast, i'm assuming i will have to splice the blue ign wire into the double connector on the run side ? and the ign terminal on the volt reg has fld stamped on it ? My ECU is 4 pin.

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IMG_0864.JPG
 
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I've just read your post and you've answered one of my Q's re: the third wire which looks like you have it on the ign side of the reg ?
 
Owning a 64 B body, I agree with all that has been posted. If you choose to stay with the stock ignition, I would use the above 2 post ballast and wire it according to the posted diagram. Lose all the other junk. My main input is to clean up any rust you see. Especially the grounds. Other wise you will have nothing but trouble. Aftermarket ignition systems like MSD eliminate the ballast completely. It gets rid of a typical failure point.
 
IGN is just switched power. We could call it RUN.
It doesn't matter much where you tap into it to power the ECU.
You could do a piggy back at the regulator, crimp a new female Packard 58 terminal with two wires,or a solder splice in the wire (with strain relief).
Piggy back some sort of second tab on the regulator is probably the easiest.
Like was said above - clean contact very important.
Also insulate with a plastic connecor or something. If there is contact with earth (ground in US/Canada English) and the key is in Run, then the alternator output and battery will discharge all the power they can down that circuit. The alternator is self protected in a way, and the battery feed on a '65 should have a fusible link, so that should be the first thing to melt - saving everything else from severe damage.

The voltage regulator is switching device. The output voltage and current flow varies. Higher voltage and more current when a stronger magnetic field is needed. Less voltage or no flow at all when a weaker field is needed.

There must be a ballast resistor or the coil will get cooked. The resistance needed depends mostly on the coil.

HEI units control current to the coil so they don't use a resistor. Capacitive discharge systems (like MSD 6, 7 etc) send power through the coil in waves (one or moer per firing). So in a different way flow though the coil primary is controlled and a resistor isn't needed. Those are the two somewhat common exceptions.
 
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