Sniper EFI Engine Wiring Harness

Sniper EFI Engine Wiring Harnesses: Built for the EFI Conversion You Actually Want to Do

When you commit to swapping out a carburetor for a modern fuel injection system, the wiring harness is what holds the entire conversion together. Sniper EFI — Holley's accessible, enthusiast-focused EFI brand — designs its engine wiring harnesses specifically to complement its own throttle body injection systems, making them a natural and reliable choice for anyone running a Sniper setup on a classic muscle car, street rod, or off-road build.

Purpose-Designed Harnesses for Sniper TBI & Sniper 2 Systems

Sniper EFI offers distinct harness configurations to match the two generations of its throttle body injection platform. The Sniper TBI Main Harness is engineered for original Sniper 1 installations. This harness includes switched 12V power, battery positive and negative, fuel pump relay, coil input, and magnetic distributor input wires. Six feet of 3/8" black braided split wire loom is also included to keep the wires protected and provide a cleaner installation.

For builders running the next-generation platform, the Sniper 2 EFI Main Harness steps things up. This harness includes a switched 12V, battery positive and ground negative, fuel pump relay, coil input wire, and HyperSpark distributor connector. The wiring is braided split loom to keep the wires protected in the engine bay, and it is intended for use on applications wanting a fuel pump relay. There is also a Sniper 2 PDM Main Harness variant intended for applications with a Power Distribution Module (PDM) that doesn't include a fuel pump relay — keeping each harness precisely matched to the powertrain management setup you're running.

Input/Output Harness: Unlocking Advanced Engine Controls

Beyond the main harness, Sniper EFI also offers a dedicated Input/Output (I/O) Harness that gives builders access to expanded control capabilities. This harness provides access to two ground trigger inputs, three ground trigger outputs, a points output, tachometer output, and digital gauge output wires. The input grounds can be used for AC kick and nitrous stage activation, while the output grounds can be used for electronic fan control or A/C shutdown at wide open throttle — features that matter enormously on a fully built classic cruiser or track car. Wires come individually labeled for easy identification , reducing the risk of wiring mistakes during installation.

HyperSpark Plug-and-Play Harness

For enthusiasts upgrading to Holley's HyperSpark ignition system alongside their Sniper throttle body, there is a dedicated plug-and-play harness solution. This harness replaces the Sniper 1 main harness and connects the HyperSpark distributor, HyperSpark coil, HyperSpark ignition, I/O connector, and the Sniper throttle body. The harness requires only one connection each to battery positive, battery negative, switched 12V, and the fuel pump, while pre-terminated connectors and a built-in 40A relay provide power to all components within the system. This level of integration is a hallmark of the Sniper ecosystem philosophy.

Why Sniper EFI Harnesses Stand Out

Sniper EFI aims to bring high-quality fuel system components to the masses, ranging from its flagship bolt-on Sniper 2 EFI systems to intake manifolds, AN fittings, fuel pumps, and other fuel system components. The harnesses are no exception — they are designed from the ground up as integral parts of the Sniper ecosystem rather than afterthoughts. The Sniper 2 platform features next-generation mil-spec style M8 positive lock connectors and a "hidden harness" design that exits from the rear of the throttle body for a clean appearance. Whether you are replacing a failed harness or completing a fresh EFI swap, these harnesses ensure that your Sniper system performs exactly as intended, right from the first start.