Car won't shut off

[werealldeadmen]

73 dOdge charger 318 won't shut off with key have to pull battery cable. Just rewired whole car wondering if I have a couple wires backwards or on wrong on ignition switch. Used painless wiring kit and it has msd box

 

[Pistol Pete]

Check over the instructions on the MSD unit, as they should cover this (or at least they used to). I remember years ago helping a buddy with his Olds that did the same thing. What happens is the alternator is backfeeding current keeping the MSD sparking along after you turn the key off. It is a simple fix though, all you need to do is install a diode in the line to block the current.

 

[howiedodat]

It may be the run wire is hot, not on keyed power. I run mine from a separate kill switch with my MSD.

 

[werealldeadmen]

Ya I used to have an external switch jus for msd butt I didn't really like the look so I went back to the stock setup and wired directly into ignition switch. now I got sumtin backwards and can't figure it out and yes I have all wiring diagrams for car still stumped

 

[smyythe68]

While it is running try cutting or removing the red ignition wire for the MSD from the spot where you connected it to the key switch. Are you running points or mag pickup?

 

[RRGTX72]

I had the same problem on my 72 Road Runner and it turned out to be the small Red switch wire on the MSD box. It needs to be a switched 12 Volt source. I ran it to my old Positive Coil wire and it now starts and stops on the key. I am running a MSD box with MSD distributor and Coil, so the old wiring for the coil on my car was not being used. If you are using your coil wire from the Ballast resistor, you can splice into the positive side and this should fix your problem. Hope this helps. Here is the link to the forum about this topic with my car.

http://www.forbbodiesonly.com/moparforum/showthread.php?t=28411