Author Topic: MSD 6A Ignition Box Wiring Question  (Read 1144 times)

Offline 7Dcuda

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MSD 6A Ignition Box Wiring Question
« on: February 23, 2017 - 12:35:50 PM »
I'm considering installing an MSD Pro Billet Distributor and an MSD 6A Ignition box in my 70 Cuda with a 440.

I've researched the MSD site for the wiring information and have learned that the MSD needs a constant 12V on the red wire.  From this site I have learned the easiest way to do that is to connect the brown and blue wires (start/run) from the ballast resistor together and then connect that to the red MSD wire.

That's easy enuf, but my question is this......my ballast resistor has 4 wires on it (2 on each terminal) I couldn't tell when looking at it last nite cuz it was dark but I assume there is a brown and blue wire there.....so if I use those as stated what do I do with the other 2 wires?  I assume they are just unused?  Not sure where the other 2 wires go and cant confirm that on my 70 Cuda wiring diagram cuz that shows a 2 pin ballast.

Am I correct that the other 2 wires are just unused and therefore just left unconnected?     
« Last Edit: February 23, 2017 - 12:44:57 PM by 7Dcuda »




Offline TelisSE440

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Re: MSD 6A Ignition Box Wiring Question
« Reply #1 on: February 23, 2017 - 01:02:00 PM »
Yes, you don't need to use them, just connect the two wires and you are good to go...

Offline 7Dcuda

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Re: MSD 6A Ignition Box Wiring Question
« Reply #2 on: February 23, 2017 - 01:45:20 PM »
Yes, you don't need to use them, just connect the two wires and you are good to go...

Cool...easy nuf.  Thanks TelisSE440

Offline cudabob496

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Re: MSD 6A Ignition Box Wiring Question
« Reply #3 on: February 23, 2017 - 01:57:43 PM »
I removed ballast resistor when I installed the MSD equipment
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Offline 7Dcuda

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Re: MSD 6A Ignition Box Wiring Question
« Reply #4 on: February 24, 2017 - 08:40:26 AM »
I removed ballast resistor when I installed the MSD equipment

Yeah, I knew the ballast resistor itself was no longer required....just wasn't sure what, if anything, I needed to do with the additional 2 wires on the ballast resistor since I had the 4 wire ballast resistor. 

Guess my question now is why do I have a 4 wire ballast when the 70 cuda wiring diagrams show a 2 wire?   

Offline Chryco Psycho

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Re: MSD 6A Ignition Box Wiring Question
« Reply #5 on: February 24, 2017 - 07:09:52 PM »
when they converted to Electronic ign they used the later system as 70 never had electronic ign , when using a 4 pin ECU you still only need a 2 wire ballast not that it matters with MSD

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Offline HP_Cuda

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Re: MSD 6A Ignition Box Wiring Question
« Reply #6 on: February 25, 2017 - 02:28:53 PM »
 :iagree:

Search my resto thread as I went through this.
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Offline TelisSE440

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Re: MSD 6A Ignition Box Wiring Question
« Reply #7 on: February 25, 2017 - 02:59:48 PM »
Cool...easy nuf.  Thanks TelisSE440

You're welcome  :thumbsup: