Master cutoff switch help

[Wicked70dart]

Well at the track this week the tech inspector had me raised the rpm to 2200 and he turned  off my master cutoff switch at the rear of the car which did not shut off the engine. The switch is wired to the positive side of the battery and does cut off power when the engine is off, my question is does the wire from the alt have to run to the cutoff switch also on the switch side of the switch and would that kill the engine when the switch is turned off if the engine is running? Thanks Matt

[abqdart]

I think you have to run a relay or diod or something off your alt....I had that same problem on a ford sometime ago and had to simply change 2 wires around going to the VR.....

[signet]

for a single pole switch you need to run a long alternator output wire to the battery before the switch,this will shut it down.

or a 2 pole switch,the second pole is rigged to the alternator field or if the amp rating on the small pole can handle the amps rigg the alternator output to that.

you could also use relays ect. but simple is better.

make sure it is all done to the positive side like the rules state.

you can fake the whole program by running a toggle switch,just remember to flip it off when your upside down unconscious.


take care

[Capt Jack]

you can fake the whole program by running a toggle switch,just remember to flip it off when your upside down unconscious.

ok, gotta admit, that made me 

do it once, do it right...live to do it again 
 

[Dartdragracer]

Are you running an electronic ignition?
I have my MSD 6AL (will work with Mopar) ignition box wired together with my water pump switch so that the engine will not fire unless the elec. water pump is on.
When the Battery disconnect is turned off, it kills all power to the car, including shutting down the engine.

[Wicked70dart]

He Guys thanks for the help, so I'm thinking about this, if I take the red wire for my msd digital 6 box that is attached to the positive battery terminal and connect it to the switch side of the master switch it should kill the ignition and all power to the vehicle, is that correct? Thanks  Matt

[guzzimike]

Matt, I believe that the MSD6AL also has in its wire bundle, an auxiliary WHITE wire. When this wire is connected to GROUND, it will shut off the MSD unit and hence, the engine. It's primarily designed as a Theft Deterrent, but maybe it can be used as an acceptable cutoff switch...

Check out Figure 4, at the bottom of page 6, in this MSD pdf document:

http://www.msdignition.com/pdf/6%20series/6series.pdf

[Dartdragracer]

Matt,
Yes, you are correct in wiring the big red wire that way, the best (proper) way to set up your battery disconnect is to have the disconnect between the (+) battery terminal and ANY live wires feeding into the car.
This insures that in case of an accident, all power can be cut-off to the car, isolating the battery , which will shutt down the engine and any possible spark sources in case of a fuel spill.

I use a Optima battery which has both top and side mounts on it so I can run one set to the external terminals for charging the battery and the other through the disconnet switch to power the car.

Hope that helps.

[signet]

the engine will not turn off if it is wired that way,unless your alternator is not up to par.

i think i gave you a few hints previously.

[67 dartgts]

Here is one I copied from another site...so I claim no credit or respobsibilty for it.

Maynard