Harnesses

An EFI system depends heavily on being supplied a clean and constant voltage source. The grounds of an electrical system are just as important as the power side. Our Holley EFI Harness Kit comes complete with the main harness, power harness and in...

An EFI system depends heavily on being supplied a clean and constant voltage source. The grounds of an electrical system are just as important as the power side. Our Holley EFI Harness Kit for your GM LS engine comes complete with the main harness...

An EFI system depends heavily on being supplied a clean and constant voltage source. The grounds of an electrical system are just as important as the power side. Our Holley EFI Harness Kit comes complete with the main harness, power harness and in...

Similar to the changes with the cam and crank sensors, the Drive-By-Wire throttle pedal connector was changed in 2008 on cars while the trucks changed in the 2007 models. Interestingly, the throttle body connector is consistent on all engines. The...

Similar to the changes with the cam and crank sensors, the Drive-By-Wire throttle pedal connector was changed in 2008 on cars while the trucks changed in the 2007 models. Interestingly, the throttle body connector is consistent on all engines. The...

This harness provides a plug and play upgrade solution for those seeking to convert to Coil-On-Plug. Additionally we have pre-installed a Power Tap for easy access to 12v, 5v Reference, and Sensor Grounds. The Ford MPFI C-O-P Main Harness has also...

This wiring harness interfaces a Holley EFI ECU to a 2V Modular Ford engine. It is meant to be used in conjunction with an injector harness, a coil harness, and ignition modules. Most stock sensors are used with this harness.Features: 1999-2004 Fo...

Main harness for 99-04 2 & 4 Valve Ford Modular (4.6 & 5.4L) Engines.Specs: Brand: Holley EFI Category: Air and Fuel Delivery Emission Code: 4 Harness Application: Ford Harness Type: Main Part Type: Fuel Injection Harness Product Ty...

The Multi Map Selector is designed specifically for use with Holley Dominator EFI systems (not HP). It allows for up to four different calibrations (Global Folders) to be selected at vehicle key-on (startup). The switch is connected into the J3 EC...

Dominator EFI GM Dual Drive-By-Wire HarnessSpecs: Brand: Holley EFI Category: Air and Fuel Delivery Emission Code: 3 Harness Application: GM, LSX Harness Type: Drive-By-Wire Part Type: Fuel Injection Harness Product Type: Drive By Wire Harn...

J4 ECU Connector26 User Programmable Inputs and OutputsSpecs: Brand: Holley EFI Category: Ignition Emission Code: 3 Harness Type: Auxiliary Part Type: Ignition Harness Product Type: J4 Auxiliary Input/ Output Harness - Connector Sub Categor...

J3 ECU Connector17 User Programmable Inputs and OutputsSpecs: Brand: Holley EFI Category: Ignition Emission Code: 3 Harness Type: Auxiliary Part Type: Ignition Harness Product Type: J3 Auxiliary Input/ Output Harness - Connector Sub Categor...

J2B ConnectorFour Additional Injector Driver OutputsFour Additional Coil Driver Outputs23 User Programmable OutputsSpecs: Brand: Holley EFI Category: Ignition Emission Code: 3 Harness Type: Auxiliary Part Type: Ignition Harness Product Type:...

Used when adding a second wide band oxygen sensor to a Dominator EFI installation.Features: J2A Connector #2 Wide band oxygen sensor harness (Fully Terminated) 23 user programmable input wires with pre-crimped ECU pins Specs: Brand: Holley EFI C...

Terminated Vehicle Harness For Digital DashSpecs: Brand: Holley EFI Category: Electrical, Lighting and Body Emission Code: 5 Part Type: Dashboard Wiring Harness Product Type: Digital Dash Harness / Adapter / Module Sub Category: Wire, Cable ...

Can Extension Harness (for Racepak and other external CAN drives)Specs: Brand: Holley EFI Category: Air and Fuel Delivery Emission Code: 5 Part Type: Fuel Injection Harness Product Type: CAN Extension Harness Sub Category: Wire, Cable and Re...

Can Extension Harness (for Racepak and other external CAN drives)Specs: Brand: Holley EFI Category: Air and Fuel Delivery Emission Code: 5 Part Type: Fuel Injection Harness Product Type: CAN Extension Harness Sub Category: Wire, Cable and Re...

Can Extension Harness (for Racepak and other external CAN drives)Specs: Brand: Holley EFI Category: Air and Fuel Delivery Emission Code: 5 Harness Application: Universal Product Type: CAN Extension Harness Sub Category: Wire, Cable and Relat...

CAN Extension Harness (for Racepak and other external CAN drives)Specs: Brand: Holley EFI Category: Air and Fuel Delivery Emission Code: 5 Part Type: Fuel Injection Harness Product Type: CAN Extension Harness Sub Category: Wire, Cable and Re...

8' Male to Female CAN Adapter Harness (for Racepak and other external CAN devices)Specs: Brand: Holley EFI Category: Air and Fuel Delivery Emission Code: 5 Part Type: Fuel Injection Harness Product Type: CAN Extension Harness Sub Category: W...

4" Male to Female CAN Adapter Harness (for Racepak and other external CAN devices)Specs: Brand: Holley EFI Category: Air and Fuel Delivery Emission Code: 5 Part Type: Fuel Injection Harness Product Type: CAN Extension Harness Sub Category: W...

12 feet long Male to Female CAN Adapter Harness (for Racepak and other external CAN devices)Features: 12' (2) connectors Wires in protective sleeve For external drivers (ideal for Racepak) Specs: Brand: Holley EFI Category: Air and Fuel Delivery...

12" Male to Female CAN Adapter Harness (for Racepak and other external CAN devices)Specs: Brand: Holley EFI Category: Air and Fuel Delivery Emission Code: 5 Part Type: Fuel Injection Harness Product Type: CAN Extension Harness Sub Category: ...

MULTEC 2 INJECTOR HARNESS - EARLY TRUCKSpecs: Brand: Holley EFI Category: Air and Fuel Delivery Emission Code: 4 Harness Application: Universal Harness Type: Injector Part Type: Fuel Injection Harness Product Type: LS Multec Style Injector ...