Restore factory-level performance and reliability with this aftermarket engine wiring harness designed as a direct-fit replacement for Ford OEM part number F81Z-12B637-BA. Built specifically for Early 1999 (E99) Ford Super Duty trucks equipped with the 7.3L Powerstroke Diesel, this harness is engineered to match factory routing and connector layout for a clean, correct installation.
Over time, original harnesses can deteriorate due to heat, vibration, oil contamination, and corrosion, causing hard starts, sensor faults, injector signal issues, intermittent misfires, and unpredictable electrical problems. Replacing the harness eliminates weak points and helps restore consistent power delivery and signal integrity across the engine management system.
This is a vehicle-specific harness — early 1999 and later 1999 (99.5) models use different wiring layouts and connectors. Please verify fitment carefully before purchase.
FITMENT
✅ Fits: Early 1999 (E99) Ford Super Duty Trucks Only
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Ford F-250 Super Duty 7.3L Diesel
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Ford F-350 Super Duty 7.3L Diesel
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Ford F-450 Super Duty 7.3L Diesel
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Ford F-550 Super Duty 7.3L Diesel
❌ DOES NOT FIT:
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1999 Ford Excursion 7.3L Diesel
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Late 1999 / 1999.5 Super Duty (different harness configuration)
REPLACES OEM PART NUMBER
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F81Z-12B637-BA
⚠️ IMPORTANT FITMENT NOTE:
This harness is vehicle-specific. Please do not assume this will fit your truck. If you are not 100% certain, message us the last 8 digits of your VIN and we will verify compatibility before you order.
Installation Notice:
No installation instructions are included. Professional installation is recommended. Please consult a qualified mechanic before attempting installation.
