Holley 558-128 EFI Ford Foxbody Main Harness

Plug and Play with fuel injected 5.0L Small Block Ford Engines

Part Number: 558-128

This harness is for fuel injected small block ford engines such as 5.0L or 5.8L Windsor powerplants. Plug and play ignition capability with Dual Sync and HyperSpark Distributors. The 5.0L Ford main harness is pre-terminated with Ford PWM IAC connector for the OEM PWM - idle air control motor commonly found on late 80's and early 90's engines. Compatible with Holley EFI Dominator, HP, and Terminator X and X Max ECU's.

Features and Benefits

• Designed for use with fuel injected small block ford engines
• Plug and play ignition capability with Dual Sync and HyperSpark distributors
• Compatible with Holley EFI Dominator, HP, and Terminator X and X Max ECU’s
• Comes pre-terminated with Ford PWM IAC connector for OEM PWM - idle air control motors
• For OEM Ford fuel injectors, use injector harness 558-209
• For TFI distributor applications, use ignition adapter 558-305

The following guide overviews all connections on the main harness. The main harness supports all the primary engine sensors, fuel and ignition for eight cylinder engines, the #1 wideband oxygen sensor, and the first four programmable input and output channels. There are two connectors for this harness designated as “J1A” (pin designations below that start with an A) and “J1B” (pin designations below that start with a B).