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Thread: 550-937F Into '89 Mustang Wiring

  1. #1

    Default 550-937F Into '89 Mustang Wiring

    I have the pigtails from a wiring harness. I'm about to start connecting the dots. I hope to keep the factory gauges and A/C working. Let me know if you see any problems with my attached plan. Thanks! HTX.pdf
    Last edited by russellbroadwell; 02-20-2020 at 07:07 AM.

  2. #2
    Join Date
    Dec 2009

    Default (Related Ford 5.0L Fox Mustang/Holley Dominator EFI Installation Post)
    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, 232°-244° duration/.623" lift/114° LSA camshaft, 11.8:1 comp, TFS R-Series FTI ported intake, BBK 80mm TB, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 200A 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/3000 RPM converter, B&M Hammer shifter, FPP aluminum driveshaft, FPP 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 MT tires.

  3. #3


    Danny, thanks for the reply! That thread is full of great information. I used that thread and the factory diagram to draw the PDF that's attached in the OP.

  4. #4


    Just did the install. Retaining factory gauges is easy. Keep your old harness laying around to look at. The manual will tell you how to retain factory gauges. They show tach color as tan/yellow for my '88. I couldn't find it, so I pulled old harness out, and seen it was green/yellow like on later models. I've investigated the old harness three times during the installation. Keep it around until your completely done all modifications. It's a lifesaver for sure. Cars running great. Had it out today. I have some fine tuning to do, but I'm very impressed with this setup!

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