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Thread: Ignition Coil Relay Wiring

  1. #1

    Default Ignition Coil Relay Wiring

    I'm wiring a Dominator Unterminated harness. I have a question about the fuel pump relay, and injector power feed. I was going to feed the fuel pump relay with the green wire, and feed the injector connector with the red wire as per wiring diagram. Is it recommended to install a relay for the Injector power? I also have CNP, I was going to feed the Ignition coil relays with the green fuel pump wire as well. Is there any other configuration others are using for coil relays? Thanks in advance.

  2. #2
    Join Date
    Dec 2009
    Location
    Connecticut
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    Holley Universal Main Harness wiring: LINK - Section 13 Wiring Appendix.
    Holley 558-307 Coil-Near-Plug Main Harness wiring: LINK - Instructions.
    https://forums.holley.com/showthread...-For-CNP-Coils (Related Forum Thread)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, 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.

  3. #3
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    I used three separate fused relays, one for the injectors, one for the fuel pump and one for the coil packs. Then I used the A2 output on the ECU to trigger all three relays.
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  4. #4
    Join Date
    Dec 2009
    Location
    Connecticut
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    I've never used the ECU's fuel pump trigger wire to directly power the pump (even if it is less than 10 amps).
    I've always used a separate relay (shown below) because that green wire is still only 14 AWG.
    The 2nd fuel pump relay is used so the fuel injectors aren't subjected to the pump's amp draw.
    It's only a 20 amp fuse and it also feeds power to the fuel injectors (& ignition coils - LSx, MOD & HEMI).
    I prefer to use 10 gauge wire due to its long length, especially for high output race pumps.
    Simply use the green fuel pump wire (+12V) to trigger your additional fuel pump relay's coil (+) terminal #86.

    https://www.holley.com/products/fuel...s/parts/12-753 (Holley 12-753 Fuel Pump Relay Kit)
    http://documents.holley.com/199r10059.pdf
    (Holley 12-753 Fuel Pump Relay Kit Instructions)
    https://www.holley.com/products/fuel...arts/30-199QFT (Quick Fuel 30-199QFT Fuel Pump Relay Kit)
    https://www.holley.com/products/fuel...s/parts/40100G (Mr. Gasket 40100G Sealed Relay Kit)
    https://www.summitracing.com/parts/pco-5593pt/overview/ (Pico Wiring 5593PT Sealed Relay Kit)
    Delphi Metri-Pack 630 Pull-To-Seat female terminals for retrofitting to a sealed relay socket connector:
    #12033997 10/12 AWG (3.0 mm²), #12066614 14/16 AWG (2.0-1.0 mm²), #12020156 18/20 AWG (0.80-0.50 mm²)
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, 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.

  5. #5

    Default

    Thanks for the input. I didn’t want to over complicate things.

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