Author Topic: MSD wired up... Won't stay running.  (Read 2128 times)

Offline Glennster

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MSD wired up... Won't stay running.
« on: July 10, 2012 - 07:57:13 PM »
 I've got something goofed up. I hooked up the 6AL, Blaster Coil and the MSD Distributor. I removed the wire harness that came from the orange MOPAR electrical box.
  I have 12V CRANKING power at the brown and blue connection with the red power wire from the 6AL, but I do not have RUNNING power once the car starts. I put a test light at that 3 way connection, when we crank it, the light is on. Once the car starts, the light goes dead.
   When we run the MSD red wire the the battery, the car runs fine. Once we unplug the red wire from the battery, the car turns off as it should.
  There is a black wire that comes out of the factory wire loom that ''was'' hooked to the Positive side of the coil. I did not hook that to anything, is that my problem?
  Did I mention that I suck at wiring?!?!?!?!?




Offline Chryco Psycho

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Re: MSD wired up... Won't stay running.
« Reply #1 on: July 10, 2012 - 08:01:32 PM »
Very weird , the blue wire should have 12v in the run position , if the black wire does hook it up , but black is usually the ground wire from the coil to the ECU

Challenger - You`ll wish You Hadn`t

Offline Glennster

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Re: MSD wired up... Won't stay running.
« Reply #2 on: July 10, 2012 - 08:09:30 PM »
Maybe I marked the wire wrong and the (factory) black wire is a ground. Maybe I should just ground it. Or should I put it on the coil ground?

Offline Glennster

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Re: MSD wired up... Won't stay running.
« Reply #3 on: July 10, 2012 - 10:03:07 PM »
 I tested the black factory wire, it goes hot when I crank the motor, so it looks like that wire is not a ground. It comes out of the factory wire loom in the center of the fire wall. It has a molded plastic where the wire attaches to the eye at the end of the wire.
  This is driving me nuts.........................................................................

Offline Chryco Psycho

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Re: MSD wired up... Won't stay running.
« Reply #4 on: July 10, 2012 - 11:21:40 PM »
so it powers up in start or run ?

Challenger - You`ll wish You Hadn`t

Offline dodj

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Re: MSD wired up... Won't stay running.
« Reply #5 on: July 10, 2012 - 11:47:44 PM »
Personally, I would open up the three way connection with the blue, brown, and red(MSD) wire and turn the ignition to run. Then with a volt meter, check to see if the blue wire has 12 volts. It should. If it doesn't, that is your problem. You will have to find out where the blue wire loses the 12 volts. Column connector, bulkhead connector. If there is 12 volts on the blue wire in the run position, you probably just have to re-make the three wire splice you made with the blue, brown, and red wires. Not likely to be the ignition switch seeing as it ran fine before the wiring changes.  :2cents:
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline Glennster

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Re: MSD wired up... Won't stay running.
« Reply #6 on: July 11, 2012 - 06:20:35 AM »
I pulled the brown, blue, red (MSD) connection apart. The brown wire is hot when the key is in the cranking position. It is not hot in the on position, I suspect that is what it should do???
The blue wire is not hot at all ! ! !
 Is there another wire I can use???
Where can I back track to find out where that wire is going dead?

It seems strange that this happened at the same time I switched everything, could a switch or something have gone bad??? Or could it be that I disconnected something that is in a loop that would get power to the blue wire?
THANKS for the help Gentlemen!!!
« Last Edit: July 11, 2012 - 07:08:24 AM by Glennster »

Offline Chryco Psycho

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Re: MSD wired up... Won't stay running.
« Reply #7 on: July 11, 2012 - 09:06:02 AM »
The blue wire is a common circuit feeding power to the voltage regulator , the alt field the ballast etc .
 Why it has no power I have no clue but you can connect to the other points .

Challenger - You`ll wish You Hadn`t

Offline dodj

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Re: MSD wired up... Won't stay running.
« Reply #8 on: July 11, 2012 - 03:40:59 PM »
The brown wire is hot when the key is in the cranking position. It is not hot in the on position, I suspect that is what it should do???
Yes that is what it should do.
The blue wire is not hot at all ! ! !
 Is there another wire I can use???
No, not really. You need that wire to go dead and kill the ignition when you turn the key to off.

The reason that wire has no power is LIKELY to be from something you did, or disturbed without knowing. As such, I would at first concentrate my efforts in the engine compartment because you likely didn't do anything inside your car. Check to see if you somehow pulled the blue wire out of the bulkhead connector. Trace the blue wire from the bulkhead connector to the place where you made the splice. Look for cracked insulation that may indicate a break. If you have a multimeter, put the switch in run, and see if you have 12vdc on the blue wire where it comes out of the bulkhead connector. Check the factory five way blue wire splice. Maybe it got pulled a little too hard during the rewire. Unplug the voltage reg and put the switch in run - do you have 12vdc there?
I'm just throwing out a bunch of things to look for as it's very difficult to logically troubleshoot electrical problems from a distance.
Hope it helps
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline Glennster

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Re: MSD wired up... Won't stay running.
« Reply #9 on: July 11, 2012 - 11:03:36 PM »
Chryco, dodj,
  I really appreciate your help!!!
 I thought we tested this wire yesterday, but maybe not. The (factory) wire that was on the the other end of the resistor (dark blue or black) was the one that had power for running. I tested it this evening, it tested hot (good), I hooked it up and went for a ride!
  The old rust bucket runs cleaner at low RPM and goes like crazy when I stand on it ! ! !
It's time for a trip to the strip....................
THANK YOU guys again for taking the time to help!

Offline dodj

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Re: MSD wired up... Won't stay running.
« Reply #10 on: July 11, 2012 - 11:06:43 PM »
 :2thumbs:
Scott
1973 Challenger  440 4 spd 
2007.5 3500 6.7 Cummins Diesel, Anarchy tuned.
Good friends don't let friends do stupid things. ........alone.

Offline Chryco Psycho

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Re: MSD wired up... Won't stay running.
« Reply #11 on: July 12, 2012 - 12:43:49 AM »
 :2thumbs:

Challenger - You`ll wish You Hadn`t