Author Topic: ignition/alternator questions  (Read 3496 times)

Offline A110235

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ignition/alternator questions
« on: December 01, 2011 - 10:28:21 PM »
Hey guys and gals.  I am in the process of starting my engine for the first time in my '71 Challenger and I have two questions.  It is not the original 383 and it probably hasn't been started in over 10 years.  The wiring in the engine compartment is a mess.  There was some stuff missing and what is there is spliced and hacked together.  A while back I started with the factory wiring diagram to fix it.

My first question is this:

Referencing this drawing below, the #22 wire from the bulkhead connector is a brown wire which hits one side of the ballast resistor and then continues as a black wire to the + terminal on the coil, and the #23 wire from the bulkhead connector is a blue wire which branches out and hits the other side of the ballast resistor, one terminal of the voltage regulator, and one of the two "field" terminals on the alternator.  Which wire is the "run" circuit and which is the "start" circuit?  Is the brown wire the "start" and the blue wire the "run?" 

factory wiring diagram


The reason I ask this is because I decided to install the mopar electronic ignition distributor and ECU and the directions say that I need to hook up the blue and brown wires to specific terminals on the new ballast resistor and ECU.

 
My second question is this:

I bought a Duralast 65A alternator (#DL7509DP) and it has two "field" terminals.   As shown on the factory wiring diagram, the blue wire hits one of the field terminals directly, and then coming off of the second terminal of the voltage regulator with this wire it hits the second field terminal.



The wiring diagram supplied with the electronic ignition ECU does not explain what to with the alternator.  I assume that the #23 blue wire  from the bulkhead connector still goes to one of the two field terminals on the alternator, but now the voltage regulator (which had a wire going to the other field terminal) is replace with the with the ECU which doesn't appear to have a wire that goes to the second field terminal on the alternator.  So my question is, does the alternator only need the one blue #23 wire connected to the field terminal and does it matter which one of the two terminals I connect it to?

I hope all this makes sense and I appreciate any help!

Kyle 


« Last Edit: December 01, 2011 - 10:36:58 PM by A110235 »



Nashville, TN         Member since October 09, 2004




Offline FY1Cuda

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Re: ignition/alternator questions
« Reply #1 on: December 02, 2011 - 12:39:44 AM »
For the first part of your question, the #22 brown wire is the start wire and the #23 blue is the run.  The current through the brown wire bypasses the resistance so the coil gets the car's full voltage at starting.  After that the blue wire runs into the ballast resistor which cuts the run voltage at the coil down to about 8 volts or something.

If you have the orange mopar ECU, keep the voltage regulator hooked up.  The ECU doesn't replace it.  The green wire from the voltage regulator goes to one of the "field" terminals (still). (I have the blue wire going to the outside field terminal and the green wire going to the terminal more toward the center, but I don't think it matters.)  The black ECU wire goes to the "-" side of the coil (with the tach wire if you have one). The blue ECU wire gets spliced into the other blue ones at the ballast resistor.

I borrowed a pic from AARuFAST on this site to show the typical placement of the box(es).
« Last Edit: December 02, 2011 - 02:13:41 AM by FY1Cuda »

Offline Chryco Psycho

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Re: ignition/alternator questions
« Reply #2 on: December 02, 2011 - 07:05:32 AM »
the picture of the alternator you posted shows the 69 single field alt the 70 has two tabs & the green wire from the second tab goes to the voltage reg & has nothing to do with the orange box at all

Challenger - You`ll wish You Hadn`t

Offline A110235

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Re: ignition/alternator questions
« Reply #3 on: December 02, 2011 - 10:42:49 AM »
Ah, I see now.  I don't know why I thought the voltage regulator went away.  So I think the drawing below should be the correct way to wire in the new ECM, right?
 


Oops, yes Chryco, I did post the wrong pic of the alternator.  The one I have looks like this one in the pic below, and I will wire it up the way it is shown.



Thanks for the help!

Kyle



Nashville, TN         Member since October 09, 2004