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Thread: Terminator/Dual Sync Setup

  1. #11
    Join Date
    Dec 2009


    Just wire the switched +12V red/white wire as instructed to a clean keyed +12V source.
    Also, ensure the Switched +12V red/white wire (pink wire - Sniper EFI) is powered in the "Run" and "Crank" key positions.
    The ignition switch must have a wire that's powered in "run" and "crank" key positions leading to the ignition system.
    The ignition switch can't start the engine, if there isn't a circuit that's powered in the "Run" and "Crank" key positions.
    The easiest way to find this wire, is to look at the wiring schematics in a factory shop manual or even a Haynes manual. (MSD Troubleshooting - Engine Run-On)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: Dominator MPFI & DIS, A/C, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/X-pipe/shorty headers, 100HP progressive dry direct-port NOS, 160A 3G alternator, Optima Red battery, LenTech Strip Terminator wide-ratio AOD/2700 RPM converter, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

  2. #12


    The wire/wires that I've had it wired to (now three different sources) are clean 12V in on & crank and off without the engine running, but something must be backfeeding into that circuit with the engine running is my only guess. ItÂ’s a stock wired car with even the factory radio, so not sure what it could be, but there's definitely 6-8 volts there with the key off and the engine continues to run even with the handheld screen shut off (but flickers occasionally).

    I guess I should ask though. Is there anyway the ECU itself could be causing this, because it seems to be the only thing left in the circuit besides normal car stuff.

  3. #13


    The stray voltage appears to be from the charging system as disconnecting either the regulator, or alternator makes the stray voltage disappear and the engine shuts down immediately. Not sure how or why, if anyone has any idea I’m open to suggestions. If not, I'll switch to a one wire system next weekend and that should solve any stray voltage problems.

  4. #14
    Join Date
    Oct 2016
    Buenos Aires, Argentina.


    The MSD box needs a diode connected in the alternator port:
    "If your engine continues to run even when the ignition is turned Off you are experiencing engine Run-On. This usually only occurs on older vehicles with an external voltage regulator. Because the MSD receives power directly from the battery, it does not require much current to keep the unit energized. If you are experiencing run-on, it is due to a small amount of voltage going through the charging lamp indicator and feeding the small Red wire even if the key is turned off.

    Early Ford and GM: To solve the Run-On problem, a Diode is supplied with the MSD in the parts bag. By installing this Diode in-line of the wire that goes to the Charging indicator, the voltage is kept from entering the MSD. The diagram below shows the proper installation for early Ford and GM vehicles."

    Click image for larger version. 

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    1970 Dodge GTX - Small Block Mopar 418ci - HP EFI Terminator TBI

  5. #15


    Excellent! I'll be doing that for sure. Who would've thought to read the instructions!?!?! I don't get lost either, I know where I'm going. Thanks! I'll let you know, but sure sounds like the fix.
    UPDATE: The diode did the trick, just like the instructions showed. Thanks for the help madmax2 & Danny. The ECU is Learning and the burnouts are getting longer.

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