wiring up a MSD Pro mag 44 - kill switch

Discussion in 'PSI Superchargers Tech Questions' started by willy200, Sep 8, 2015.

  1. willy200

    willy200 Member

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    Whats the best way and parts to use for a kill switch on a Pro Mag 44
     
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    willy200, Sep 8, 2015
  2. Mike Canter

    Mike Canter Top Dragster
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    The main thing you want to do is to short the positive terminal on the coil to ground. If you have a 8973 or a Grid then all you need to do is shut off the 12 volts to either of those and the motor will shut down and without that I prefer the MSD Shutoff Relay/solenoid that only requires a toggle switch and sorts the coil to ground. That coil positive terminal has only 12 volts but at 44 Amps and you can weld with that.
     
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    Mike Canter, Sep 8, 2015
  3. Nitro Madness

    Nitro Madness Super Comp

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    I have had the Cole-Hersey relays (sold by MSD) fail due to shake and vibration....and they fail to ground position if the spring breaks which intermittently kills the ignition....I carried spares too but always hated to lose a run due to an electrical failure...

    When I built my current car I got a cylinder type switch from Ken Wright in West Liberty, Iowa....pretty sure he makes these for the tractor guys....it's very similar to the old SAE barrel style switch with the internal forks that engage and dis-engage....has a fairly long stoke with detents for both on and off positions.....call Ken Wright at 319-627-2688

    This is a pretty fool proof setup with just a single ground wire to the switch....rather than a powered circuit to turn it on and off...
     
    #3
    Last edited: Sep 9, 2015
    Nitro Madness, Sep 8, 2015
  4. hotrod796

    hotrod796 New Member

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    I used the MSD kill solenoid (not the air solenoid) and had some weird ignition stuff happen. I pulled that, bought a good toggle switch and use that to ground the mag. Been that way for 50 runs with no problem. A friend has the same set up on his dragster with no issues.
     
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    hotrod796, Sep 13, 2015

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