Car won't turn off.

[combatsp]

I have a 1968 Charger 440 I am preparing to sell. I hooked up a new MSD6al2 ignition with MSD distributor. I fired the car up and it ran perfectly. When I turned the key to the off position the car continued to run as if I never turned the key off. I read that there can be bleed back into the system that will cause this. I installed a 4 prong ballast resistor as directed by the instructions and it still will not turn off. I had to remove the negative battery cable to stop the car from running.

I noticed that the battery cables throw sparks when I remove them even if the car is off. Never noticed that before. I checked my wiring job versus the instructions and don't see any problems but still not ruling my screw up out. Could it be the started relay or ignition switch? Thanks.

 

[MT_Mopar]

There is a section on page 7-8 about engine run-on and diode installation. Installing a diode may fix your problem - only talks about GM and Ford though.
http://www.msdignition.com/uploadedFiles/MSDIgnitioncom/Products/Ignitions/6421_instructions(1).pdf

 

[440roadrunner]

There is a section on page 7-8 about engine run-on and diode installation. Installing a diode may fix your problem - only talks about GM and Ford though.
http://www.msdignition.com/uploadedFiles/MSDIgnitioncom/Products/Ignitions/6421_instructions(1).pdf

This only has to do with a "charge light" backfeed which a 68 Charger does not have. I would disconnect the "small red" at the MSD. if the engine quits, then you have a problem in the vehicle, either some wires crossed, something added, or a bad ignition switch.

If it "runs on" with the MSD "small red" unhooked, it's a problem in the MSD itself

 

[kiwigtx]

There is a section on page 7-8 about engine run-on and diode installation. Installing a diode may fix your problem - only talks about GM and Ford though.
http://www.msdignition.com/uploadedFiles/MSDIgnitioncom/Products/Ignitions/6421_instructions(1).pdf

I experienced this when installing an MSD to my friend's FORD a couple of years ago.
Install the diode if able to....it works.

 

[747mopar]

This only has to do with a "charge light" backfeed which a 68 Charger does not have. I would disconnect the "small red" at the MSD. if the engine quits, then you have a problem in the vehicle, either some wires crossed, something added, or a bad ignition switch.

If it "runs on" with the MSD "small red" unhooked, it's a problem in the MSD itself

This is the first thing I'd do, like he said make sure the IGN wire is only putting out 12V when the ignition switch is in run.

 

[440roadrunner]

I experienced this when installing an MSD to my friend's FORD a couple of years ago.
Install the diode if able to....it works.

I'm trnny tell ya, OK? Mopars do not have "charge' idiot lights. This does not apply.

 

[MT_Mopar]

http://www.msdignition.com/page.aspx?id=3296

 

[Dennis H]

First I will admit ignorance. Now, is there a difference between run-on and a motor that continues to run? I thought run on was more like dieseling.

 

[Sixpactogo]

Sounds to me like the ignition switch is faulty. My wife had a Chevy Malibu that would not turn off and it was the switch itself that failed. Never had it happen with a Mopar though

 

[combatsp]

http://www.msdignition.com/page.aspx?id=3296

View attachment 276931

This is what I installed to stop the run on but it is still running.

- - - Updated - - -

First I will admit ignorance. Now, is there a difference between run-on and a motor that continues to run? I thought run on was more like dieseling.

My car continues to run as if I never turned the key off. It is not like dieseling.

- - - Updated - - -

It may sound stupid but the first thing I am going to try is the spare key. The regular key I use is pretty worn down and I wonder if it isn't engaging the tumbler to turn the car off.

 

[747mopar]

If it wasn't engaging the tumbler the key shouldn't even turn?

 

[Shorthorse]

Start at the + side of the coil with the key "off" and check for 12V. Then work backwards (diagram "B"). Also, what did you do with the dark blue/tracer field wire from the alternator?

http://www.mymopar.com/downloads/1968/68ChargerA.JPG
http://www.mymopar.com/downloads/1968/68ChargerB.JPG

 

[Glenn's hc]

Remove everything you recently did as to the msd, and return it back to stock , see if it works , shuts down properly . Then with a fresh start reinstall the msd ,you are wiring something wrong and feeding power directly to the coil.

 

[440roadrunner]

Remove everything you recently did as to the msd, and return it back to stock , see if it works , shuts down properly . Then with a fresh start reinstall the msd ,you are wiring something wrong and feeding power directly to the coil.

Absolutely NOT necessary. MSD does NOT work by powering the coil

- - - Updated - - -

Start at the + side of the coil with the key "off" and check for 12V. Then work backwards (diagram "B"). Also, what did you do with the dark blue/tracer field wire from the alternator?

http://www.mymopar.com/downloads/1968/68ChargerA.JPG
http://www.mymopar.com/downloads/1968/68ChargerB.JPG

Pretty much what I said earlier, YES!!

 

[niteshift70]

Sounds like a breakdown within the ignition switch. This ain't engine run on. The arcing on the terminals is telling you you still have power TO your msd which your ignition switch is supposed to cut off but hasnt.

 

[niteshift70]

Or you have a constant 12v supply hooked up to the ignition ON supply to the msd.

 

[combatsp]

I think I found the problem. I have the small red wire coming from the MSD box hooked to the starter relay. It is supposed to be hooked to a "switched 12v". Where do I find a "switched 12v" to hook the wire to?

 

[niteshift70]

Should be able to find one off your fuse box. Use your test lite or meter to find a terminal that is hot when the key is ON and dead when OFF. The lead to the coil is a good example.

 

[niteshift70]

The original lead.

 

[combatsp]

I found a wire that has 12v when the ignition is on and hooked it up. Now it doesn't start. Anyone want to buy a car "as is". lol