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-10% Main Harness, LS1 / LS6

This harness is designed for Chevy LS and late-model truck engines that have a 24-tooth crank sensor and a single-pulse cam sensor. In most cases, that includes LS1, LS6 and truck engines up to 2007. You can normally identify which crank sensor you have by observing the connector on the engine block. A black connector indicates a 24-tooth wheel, but a gray indicator indicates a 58-tooth wheel. If you have the 58-tooth version you will want to opt for the LS2/LS3/LS7 harness instead.

This LS1 main harness makes connecting the Holley ECU to your LS1 a breeze! It plugs directly into the Holley ECU and then provides direct-fit connections for the stock sensors, including:

  • Manifold Air Pressure
  • Throttle Position Switch
  • Coolant Temperature Sensor
  • Crank Sensor
  • Cam Sensor
  • Stock Ignition Harness (Even/Odd)
  • Idle Air Control
  • Manifold Air Temperature

Other connectors are included that are direct-fit for the following Holley sensors, available separately:

  • Fuel Pressure Sensor
  • Oil Pressure Sensor
  • Wideband Oxygen Sensor

This harness is included as part of the HP EFI ECU and Harness Kit, GM LS1 (550-602).

Not Sure? Review this product documentation before you buy!

Wiring Diagrams for
Holley ECU's and Harnesses

Harness TypeMain
Also IncludedIntegrated 40Amp Relay (Order 534-26 if replacement ever required)
ApplicationGM LS1 Engines (24-Tooth Crank Wheel, Single Pulse Cam Sync. Will also work with matching LS6 and Truck engines 1997-2007)
LengthMost main harnesses allow a maximum of 5 feet between the back of the cylinder head and the ECU mounting location (as the wire travels.) This is only a rough estimate and nothing should be installed before you have the harness in hand.
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Main Harness, LS1 / LS6

  • Views: 18245
  • Brand: Holley EFI
  • Product Code: 558-102
  • Availability: In Stock
  • $627.00
  • $563.95