Crank position problem/question Mopar Harness Kit

dickdale

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I've noticed that the ignition switch of my 70's Plymouth doesn't give 12 volts to a few wires when the key is in the crank position.

The Mopar Harness Kit (MHK) manual says:
N - Color: LightBlue/Tan wire goes to the Starter Relay Control: Connect to 12V source provided only when in crank position. Requires a 12V input from ignition switch to control the starter relay only when key is in crank position.
N - Color: Pink/Brown wire goes to the IGN Relay Control: Connect to 12V source provided when in crank and run position. Requires a 12V input from ignition switch to control the ignition relay when key is in de the crank and run position.

The EZ-wiring harness says:
IGN SW PWR=RED goes to RED on IGN SW
IGN SW IGN=PINK goes to BROWN on IGN SW
IGN SW ACC=ORANGE goes to BLUE on IGN SW
IGN SW ACC=BROWN goes to BLACK on IGN SW
IGN SW START=PURPLE goes to YELLOW on IGN SW

Just to be shure, does the LightBlue/Tan of MHK go to YELLOW/PURPLE and the Pink/Brown go to RED?
I probably don't want to use the PINK/BROWN wire because of the 12V signal getting lost when putting the IGN SW in the crank position?

harness kit manual.jpg wiring harness.png
 

5.7 hemi

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Connect IGN 1 and IGN 2 together. That will give ya 12 volts at cranking and running.
 

dickdale

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I’ve spoken with Sound German Automotive and he recommends using a Hella time delay unit. Part number 5HE 996 152-131. That should solve the problem.
 

5.7 hemi

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You want 12 volts at run and crank, connect ign 1 and ign 2. Done! You’ve just saved money for another part for the car.
 

dickdale

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You mean using the LightBlue/Tan of MHK go to YELLOW/PURPLE and the Pink/Brown go to RED?

By doing that the MHK will have a constant 12V which can draw the battery. Don't want to do that.
 

What’s up dock

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Just wire in a simple relay. Power and ground to relay, then use the "start" ignition to switch on the relay, feeding power to the "run" side of the ignition.
 

What’s up dock

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I have a 73 challenger column on the bench right now, so I verified they wires if you are wondering.
Ign 2 circuit only provides power when in start. When you release the key from the start position, Ign 1 takes over.
So, as far as your wires in the mopar "N" group, LT blue/tan will go to start, and your Pink/tan wire to Ign 1 AND Ign 2. This will provide continuous voltage in run and start cycles of the ignition.
Don't forget the other wire in "N" of the mopar wires is for neutral or clutch safety. The red wire is power output, 20 amps.
 

6872n73

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I think you'll need a diode on the start leg so that the on position doesn't back feed the starter.
 

What’s up dock

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I think you'll need a diode on the start leg so that the on position doesn't back feed the starter.

No diode needed. Think of how your ballast resistor works. Ignition one is the ""run" circuit . Accessories are on , along with the hot for the ballast, which feeds ignition. When you turn the key to "start", ignition one is now completely dead, ignition two sends power to the ballast. The actual "start" circuit is different, so there is no back feeding.
With this in mind, think back to what happens when your ballast resistor fails. You have no spark while cranking, but sometimes it will fire when you turn the key back to run. That's because you don't have the voltage from "ignition two" passing through the ballast. And what did everyone do to get home with a bad ballast........you tied the two together!
You had to do the same thing to run an MSD box.
 

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