Quick Distributer Wiring Question

[Stroked68Dart]

I have 2 quick questions I am hoping you guys can help me with. I have an extra MOPAR ECU box I am wanting to use on a non-Chrysler motor in a race car I inherited. I know... I know... I should get a Chrysler but I don't have the money right now and am having to make due with what I have. Below are my questions:

1. Do one of the 2 ECU wires going to the distributer just carry + current to the distributer? Essentially I am needing to know what the wires attached to the ECU posts 4 & 5 do (see pictures).

2. and a related question is, what is the color coding for the wires that go into the distributer? This is an out of the box MOPAR distributer with wires. I believe the wires going into the distributer I have are black and red or black and brown. See photos for more information.

In the attached photos I have tried to circle in yellow the areas I am trying to understand better.

As always, thank you very much for your help!
Bill

 

[krazykuda]

The light blue wire goes to the input side of the ballast resistor.

the black wire goes to the Coil negative.

The green wire is only needed for a 4 pin ballast, cut it off if you have a two pin ballast.

The other two wires go to the distributor...

 

[Stroked68Dart]

The light blue wire goes to the input side of the ballast resistor.

the black wire goes to the Coil negative.

The green wire is only needed for a 4 pin ballast, cut it off if you have a two pin ballast.

The other two wires go to the distributor...

Hi KrazyKuda,

I am needing to understand what the two wires to the distributer do. Is one just carrying positive current and the other getting the trigger signal from the rotor or ?? thank you for your help O

 

[69_340_GTS]

Pin 5 gets the black wire. Pin 4 gets the orange wire.

Wiring diagram shows black wire from dist connected to the grey with black tracer wire from the box, and orange wire from dist connected to the brown with white tracer wire from the box.

 

[67Dart273]

I have 2 quick questions I am hoping you guys can help me with. I have an extra MOPAR ECU box I am wanting to use on a non-Chrysler motor in a race car I inherited. I know... I know... I should get a Chrysler but I don't have the money right now and am having to make due with what I have. Below are my questions:

1. Do one of the 2 ECU wires going to the distributer just carry + current to the distributer? Essentially I am needing to know what the wires attached to the ECU posts 4 & 5 do (see pictures).

NO. The distributor generates an AC wave, which goes both negative and positive, but in pulses matching when the cylinders should fire, IE determined when the relutor tip passes the pickup. POLARITY MATTERS because turning those wires around will affect timing in relation to the rotor and cap. Google "rotor phasing."

DO NOT go by color code. Go by the physical drawing of the connector. If you are not using a Mopar distributor, you will have to try it one way or the other to get phasing correct. Again.......Google "rotor phasing"

2. and a related question is, what is the color coding for the wires that go into the distributer? This is an out of the box MOPAR distributer with wires. I believe the wires going into the distributer I have are black and red or black and brown. See photos for more information.

DO NOT go by color code. Go by the PHYSICAL drawing of the connector on the ECU



Also, you want to make sure your box is 4 pin, not 5 pin. This is not physical pins, this is "whether" it's a newer box and doesn't connect the 5th pin. You will have to take the box, and a multimeter, and determine if the 5th pin is connected or is "infinity."

The wiring and basic function of a newer 4 pin Mopar box IS EXACTLY THE SAME as a GM HEI module except that you don't "have" to use a coil ballast with an HEI

One of our members here derived this nice neat diagram after my crappy hand drawn one LOL

To compare the two, if you disregard the coil resistor for a moment, the wire functions are the same. "4 wires" plus ground, so you have.........

1....Coil + and battery power supply

2....Coil NEG connection

3....Distributor connection A the "bare side" of the distributor connector

4....Distributor connection B the "insulated side" of the distributor connector

GROUND. The ECU CASE must be grounded. The HEI MUST be grounded through the two mounting holes.

AGAIN do NOT go by colors. Go by the physical drawing of the box

See post below.........for testing...... no resistor. NOTICE that the distributor connector is drawn to represent one side "bare" at the top of the connector, in the drawing, the bottom side "insulated."

The terminal "X" on the box corresponds to your original drawing labeled "Unused in 4 wire ECU. green red tracer"

 

[67Dart273]

Maybe this helps, maybe not........

Here's a post I made about the simplest way I know to get across testing the ECU/ ignition parts

http://www.forabodiesonly.com/mopar/showpost.php?p=1970917976&postcount=6


You need a coil, the ECU and the distributor

Lay it out on the bench. Follow the diagram. Find the two distributor pickup terminals on the ECU. Hook them to the distributor

Hook the ECU case to battery NEG

Coil does NOT need grounded

Distributor does NOT need grounded.

Hook coil + to the power lead terminal on the ECU. Get a clip lead hooked there and let dangle. This is your battery "hot" when you are ready

Hook something from coil "case" to a probe for testing spark.

Hook up your power clip lead. Twist the distributor shaft while holding the test probe near the coil tower. The thing should make sparks

If not, unhook distributor. Take first one, then the other pickup clip leads, and "tap tap" ground them at the battery connection. Coil should make 1 spark each time you do so.

If not, try another coil. If that does not fix it replace the ECU

IF you hook it all up and it WORKS, then there is something AFU in the car harness. SUSPECT a bad ECU connector OR a bad DISTRIBUTOR connector
=============================================
This is all you need to test the basics of the ignition. You can easily test the ballast separate. A battery, the ECU, distributor and a coil, and of course some test leads

Below, the basic diagram for a 4 pin ECU

Below, the wire for testing spark. I use my 12V test light. No, LOL the spark won't blow up the bulb

Below, the ground connection. ALL you need is one wire from batt NEG to the ECU case

Below, the two distributor connections. In the car these are polarity sensitive, but for testing does not matter

Below, the coil NEG connection

Below, battery PLUS connection, one wire to this terminal of ECU and jumpered over to + side of coil

Below, all hooked up and ready to test (except for battery ground). Should produce sparks at least 3/8" and typically 1/2" long

Below, distributor "one wire" test. I have removed the other distributor wire for simplicity. Take the bare connector end or this clip lead (the yellow) and with everything hooked up, ground it repeatedly. Each grounding should result in a spark (In this photo you need to hook up the ECU ground wire, I left it off for the photo)

 

[Stroked68Dart]

Wow guys!! this is EXACTLY the info I needed!! Thank you very much!