Replace an aging, damaged, brittle, or unreliable factory engine wiring harness with this SWAG Performance aftermarket engine harness assembly for select late-1999 through 2001 Ford 7.3L Powerstroke Diesel trucks.
After decades of engine heat, vibration, oil exposure, and repeated heat cycles, the original engine harness can develop damaged insulation, brittle wiring, loose connections, or poor terminal contact. These problems can create difficult-to-diagnose electrical issues including intermittent injector operation, rough running, sensor faults, erratic performance, and no-start conditions.
This replacement harness is designed as a direct-fit alternative to Ford YC3Z-12B637-BA, restoring the primary engine wiring connections without trying to repair multiple deteriorated sections of the original harness individually.
Key Features
- Complete aftermarket engine wiring harness assembly
- Direct-fit replacement for the original engine harness
- Designed for select 1999.5-2001 Ford 7.3L Powerstroke Diesel applications
- Specifically for California emissions vehicles
- Specifically for automatic transmission applications
- Factory-style connectors and routing for straightforward installation
- Replaces deteriorated, brittle, damaged, or previously repaired engine wiring
- Helps restore reliable electrical connections between engine sensors, injectors, controls, and related systems
- Excellent option when the discontinued original Ford harness is no longer available
Replaces / Interchanges With
Ford OE Part Number:
- YC3Z-12B637-BA
- YC3Z12B637BA
Vehicle Fitment
Designed for select:
- 2000 Ford F-250 Super Duty 7.3L Powerstroke Diesel
- 2000 Ford F-350 Super Duty 7.3L Powerstroke Diesel
- 2001 Ford F-250 Super Duty 7.3L Powerstroke Diesel
- 2001 Ford F-350 Super Duty 7.3L Powerstroke Diesel
- Other applicable Ford 7.3L Powerstroke Diesel applications originally equipped with YC3Z-12B637-BA
Required Configuration
Vehicle must have:
- 7.3L Powerstroke Diesel
- California emissions
- Automatic transmission
- Build date after 10/25/1999
Important Fitment Notice
Do not order by model year alone.
Ford used multiple engine harness configurations during the 1999-2001 7.3L Powerstroke Diesel production run. Harness selection can vary according to vehicle build date, emissions configuration, and transmission type.
This harness is specifically intended for California-emissions, automatic-transmission vehicles built after 10/25/1999.
It is not intended for Federal-emissions trucks, manual-transmission trucks, or earlier-build applications requiring a different harness.
We strongly recommend verifying the vehicle's VIN, build date, emissions label, transmission, and original harness part number before ordering.
Why Replace the Complete Harness?
Electrical problems on an older 7.3L Powerstroke Diesel can become extremely difficult to diagnose when the original wiring has deteriorated in multiple locations. Repairing one damaged connector or section of wire may solve one symptom while leaving additional aging sections behind.
Replacing the complete engine harness provides a more comprehensive repair for vehicles suffering from wiring deterioration and may help correct symptoms related to poor engine-harness connections such as:
- Intermittent engine operation
- Injector dropout
- Rough running
- Intermittent no-start conditions
- Sensor circuit faults
- Poor connector contact
- Damaged or oil-soaked wiring
- Brittle or cracked wire insulation
- Previous wiring repairs or splices
For a late-build 7.3L Powerstroke Diesel that requires YC3Z-12B637-BA, this SWAG Performance replacement harness offers a practical solution to replacing a factory wiring assembly that has become increasingly difficult to source.
