Key on wire for MSD ignition and one wire alt

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modtopcuda

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I am trying to figure out what wire I should use for key one for the MSD ignition. I am using a one wire alt so basically am not using the ballast or regulator. There are some wires going to them but not sure they do anything. I tried using the radio wire but when the key is turned it kills power to that wire. The car does start when jumped. Thanks for any help.
 
The wires that ran to the ballast resistor,tie them together with the small red msd wire. Thats it.
 
The one your missing goes from starter relay,marked ign,to msd red wire also.
 
hangn0ut said:
The one your missing goes from starter relay,marked ign,to msd red wire also.
Click to expand...


NEGATIVE. No wire goes to the starter relay

On ALL these Mopars there are only TWO wires which supply underhood ignition loads. This includes ignition, voltage regulator, alternator field, electric clutch if used, and idle solenoid if used, as well as "smog doo dads" on some years.

These are the "ignition run" IGN1 wire, some years (but not all) is DARK BLUE. This feeds the "jumpered" wires of your 4 pin ballast, the alternator field (blue) and the blue VR wire

BUT THIS WIRE GOES COLD during cranking.

The SECOND wire is BROWN, IGN2, and this "used to" go to the coil + side of the ballast. THIS IS THE ONLY source of ignition during "cranking."

You must jumper those two together, and hook them to the MSD small red.
 
And that brown wire originates,,,,,at the starter relay. Goes hot as relay is energized.
 
And that brown wire originates,,,,,at the starter relay. Goes hot as relay is energized.
 
hangn0ut said:
And that brown wire originates,,,,,at the starter relay. Goes hot as relay is energized.
Click to expand...

NO IT DOES NOT ORIGINATE AT THE STARTER RELAY. NO!!!!! It (the brown wire) comes FROM THE IGNITION SWITCH, THROUGH THE BULKHEAD CONNECTOR

WHY you do not want to use the "start" wire in place of the brown bypass wire:

AFTER the car starts, and the key goes back to "run" IF you use the "start" wire for your bypass, the "ignition" voltage coming from the "run" wire WILL BACKFEED back to the starter relay and try to keep it energized. This is not such a big problem with an automatic car "while" the shifter is in something other than park or neutral. But with the relay terminal grounded by the NSS, it has a path to ground
 
Hmmm,if ya say so. But my resources clearly show a wire from starter relay to positive side of coil via ballast resistor. Wired my junk this way forever and no problems. How can power in the load circuit of a relay possibly energize said relay?
 
hangn0ut said:
Hmmm,if ya say so. But my resources clearly show a wire from starter relay to positive side of coil via ballast resistor. Wired my junk this way forever and no problems. How can power in the load circuit of a relay possibly energize said relay?
Click to expand...

1..........Post "my resources". Mine are the factory service manuals

2..........I'll ignore that

3...........Really? OK I will explain.

The starter relay has two "push on" connectors. ONE of them is powered from the "start" wire coming from the key, often yellow colored. It powers the relay for cranking, and that is the ONLY thing that wire does

The GROUND side of the relay is only activated on 70/ later stick cars when you push in the clutch. On automatics, it's grounded in neutral or park.

THIS MEANS that the power to the ignition system (the "ignition run") which is HOT will FEED BACK over your "starter relay" wire and PROVIDE POWER TO THE STARTER RELAY. If the clutch is depressed, or if the automatic is in neutral or park, the relay WILL HAVE A GROUND PATH, and since it has power coming in from the ignition wire, IT WILL ENGAGE the starter.
 
here is how my dart was wired...

71DartIgnitionWiring.jpg
 
Thanks Joe. The first (top) part of Joe's photo is how "many" years are wired. There are a few years where some of the colors are different

71DartIgnitionWiring (1).png


The big red is main power coming "into" the ignition switch, is hot at all times.

The big black is "accessory" power going out, hot in "run" or accessory

Dark blue is ignition run, hot ONLY in "run" but dead in "start" THIS IS THE ROOT OF THE PROBLEM..........this wire goes dead in start

Yellow is your "start" wire fires the start relay. DO NOT USE for any other purpose

Brown is the wire in question. It is hot ONLY in start but comes off a SEPARATE contact in the switch, that is "a separate switch" within the "can" that "is" the ignition switch. This wire only goes one place.........to the coil + side of the ballast relay.
 
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Thanks for the lesson. Always a little room left in the brain to learn something. My resource is the DC engine books. Factory race engineers. Yeah all my stuff is highly modified. One outa four has a key. Might drop a mag in or who knows? I'll look that up in my FSM. Thanks.
 
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