Car runs after main switch by battery is off

[briankaplan]

Just want to run this by you guys to see what you think.
The car still runs after I turn off the main switch in back
by the battery. Don't remember it doing it with the MSD 6 box.
Now with the 6AL box it just keeps running.
Do I need a relay in line for the 6AL box. That should cut
power right away.

 

[Cuda 69]

I had that problem on my race car when I first started
(not good for Tech) and found the problem to be the motor was running
off of the alternator when the battery was disconnected. If you have
a two part switch at the battery try breaking the alternator output
wire with the other part of the switch or put a switch in your switch
panel to work on the alternator output. I nolonger use an alternator
so that is how I fixed my problem. Hope this helps.

69 Cuda, 383 w/2 4bbls, Keisler 5 speed, 456 gears, for the fun of it!

 

[69signetv8]

Perhaps...but not 100% sure!!

MSD run-on? :scratch: Although it's stated not requred, are you using a Bal resistor with you 6al. On page 9 of MSD instructions it states that "very little voltage" is required to keep the unit powered to supply power to your coil. (even with the key off) I would think your alt passing current through your voltage reg is just enough to keep your 6al going. It also states if you have a Chrysler with run-on (then use the dual resisitor)

 

[GoodysGotaCuda]

Sounds like your alternators output is not routed to the battery side of the switch,

 

[340_Scamp]

yep, sounds like the alt. is keeping it running. I had the same problem with my Dakota. I figured out that you could pull the 140 amp main fuse while at the track to bypass the alt. Haven't move the battery on my Scamp yet. I would guess you could pull the alt wires from the back when you are at the track?

 

[sweatybetty]

maybe a relay that kills the power to the ignition when you shut off the battery.

 

[moparlee]

I really need to get the MAD electrical "Mopar style" diagram posted on some sites. It works perfectly. You need to run the altanator wire all the way back the battery. It's hard to explain. I need to get that page scanned and then posted. I'm also using the PHORD relay in the trunk so that the big battery cable is dead unless I'm cranking. I'm also still using the original mopar relay on the firewall, cause it does a lot of things like feed the power inside the car and run the phord relay in the trunk. So it it's still doing what it was intended to do, but I'm also running the MSD box off of it also.

Lee