Just finished installing MSD 6AL ignition system in my bird. IT WILL NOT SHUT OFF WHEN I TURN IT OFFF!

The black and red wire cominging out of the distributor were connected to the white and red wire onthe MSD box. there was another wire connected to the positive side of the coil . I believe was the switch . I connected it to the red wire from the box . Engine starts fine and runs super but wont shut off until I disconnect the 2 wires. I connected a test light and its burns bright and shuts off when I turn key off. When running it is bright and when I turn key off the light gets dim but it does not go out completely  and continues to run. I have checked everything and it is where it is supposed to be. (i guess that is and incorrect statement because the car runs continiously) . I have taylor spiral wires, Blaster 2 coil, new 46 Platinum plugs and a pertronix ignition . Any suggestions appreciated. Thanks for any input. 

55Birdman  Hickory NC

have you changed out the wiring harness to a late style gm type harness?if so and if you are using a gm tpye altenator you will need to put a one way diode in the excitor wire to the altenator,what may be happening is the altenater will feed back to igntion when you shut down.i had this problem when i switched out harnesses and noticed the diode in the kit.it seems when you go to a one wire alt you don't need the diode,but if you go to the three wire setup on the alt,it needs that doide.hope this helps.jim

Sounds like the same basic set up that I have. Do you have a GM internally regulated alternator also? If so you may be getting feed back from the alternator which is powering your ignition.



Not saying that is your problem because I don't know how you are wired up but that was what mine did. I had to install a diode in the alternator wire so it wouldn't flow backwards.



I'll have to go out to the garage to see what diode I used, can't remember (it's that old timers disease).





Johnson Rod



Southern California

OK I'm back. I got my diode(s) at Radio Shack part # 276-1661. Hope that helps you.





Johnson Rod



Southern California

I am still using my generator. Is that bad?

55Birdman  Hickory NC

No that's not bad, but it sure blows my theory (and Jim's) all to hell. Still sounds like something is back feeding the ignition, but I do not know what.





Johnson Rod



Southern California

it seems to me you could still be getting feed back from your generator,but i,m no expert on that;you may want to try your test lite at the generator after you shut down to see if you are still getting juice at that point.it may still need a diode installed,jim

I installed a set of 113 heads and a blue thunder intake and carb earlier. My friend bought the MSD for me and he and I installed the thing over the last few days until we got to this point. The car ran super before we did the msd. When it does run now it seems a bit rough. Now you know the whole story.  

55Birdman  Hickory NC

i don't think the intake or carb has anything to do with it;you are feeding back for some reason;you had no problem until you install the msd box,so that's a good place to start;if it ran good without the msd i'm wondering why you fell you need it;i'm not sure that is an advantage on a basicly stock setup;if i understnd correctly,it do not require but very low voltage to run that computer box,so you need to search out where feed back would originate and most logical point would be the charging system.i would start there.jim

Been a while since I worked with it but recall you can hook the ignition resistor to the wrong place on the solenoid.  Cutting off the switch will not interrupt power to the coil.

TC

You gotta have the right tools and know how to use 'em.

TC - Austin, Texas