{"product_id":"holley-efi-main-power-harness-for-avenger-hp-dominator-efi-13-ft","title":"Holley EFI Main Power Harness for Avenger, HP \u0026 Dominator EFI – 13 ft.","description":"\u003cp\u003eThe \u003cstrong\u003eHolley EFI Main Power Harness for Avenger, HP \u0026amp; Dominator EFI – 13 ft.\u003c\/strong\u003e provides the primary battery power connection required for Holley EFI engine management systems. This heavy-duty 10 AWG harness is required for HP EFI and Dominator EFI ECUs and is also compatible with Avenger EFI systems. Its 13-foot length offers flexible routing while maintaining reliable power delivery directly from the battery.\u003c\/p\u003e\n\u003cp\u003eThe harness is protected by a 40-amp fuse and enclosed in braided split loom to resist abrasion in demanding automotive and off-road environments. Two 3\/8-inch battery ring terminals and heat shrink tubing are included for a clean, secure installation. For maximum ECU performance and reliability, Holley specifies that this harness must be connected directly to the battery terminals.\u003c\/p\u003e\n\u003ch4\u003eIncludes:\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e(1) Holley EFI Main Power Harness\u003c\/li\u003e\n\u003cli\u003e(2) 3\/8\" Battery Ring Terminals\u003c\/li\u003e\n\u003cli\u003eHeat Shrink Tubing\u003c\/li\u003e\n\u003cli\u003e40-Amp Fuse Protection\u003c\/li\u003e\n\u003cli\u003eBraided Split Loom Covering\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003cdetails class=\"details\"\u003e\n\u003csummary\u003e\u003cstrong\u003eSpecifications\u003c\/strong\u003e\u003cspan class=\"svg-wrapper icon-plus\"\u003e\u003csvg width=\"14\" height=\"14\" viewbox=\"0 0 14 14\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath class=\"vertical\" d=\"M2.75 7H11.25\" stroke=\"currentColor\" stroke-width=\"var(--icon-stroke-width)\" stroke-linecap=\"round\"\u003e\u003c\/path\u003e\u003cpath class=\"horizontal\" d=\"M7 2.75L7 11.25\" stroke=\"currentColor\" stroke-width=\"var(--icon-stroke-width)\" stroke-linecap=\"round\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/span\u003e\u003c\/summary\u003e\n\u003cdiv class=\"details-content rte\"\u003e\n\u003ctable class=\"custom-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eDetails\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eManufacturer\u003c\/td\u003e\n\u003ctd\u003eHolley EFI\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003e558-308\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Type\u003c\/td\u003e\n\u003ctd\u003eMain Battery Power Harness\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHarness Application\u003c\/td\u003e\n\u003ctd\u003eUniversal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHarness Type\u003c\/td\u003e\n\u003ctd\u003eMain Battery Power\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCompatible EFI Systems\u003c\/td\u003e\n\u003ctd\u003eAvenger EFI, HP EFI, Dominator EFI\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWire Size\u003c\/td\u003e\n\u003ctd\u003e10 AWG Automotive TXL\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHarness Length\u003c\/td\u003e\n\u003ctd\u003e13 Feet\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFuse Rating\u003c\/td\u003e\n\u003ctd\u003e40 Amp Maximum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProtection\u003c\/td\u003e\n\u003ctd\u003eBraided Split Loom\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCategory\u003c\/td\u003e\n\u003ctd\u003eIgnition\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003chr\u003e\n\u003cdetails class=\"details\"\u003e\n\u003csummary\u003e\u003cstrong\u003eFitment\u003c\/strong\u003e\u003cspan class=\"svg-wrapper icon-plus\"\u003e\u003csvg width=\"14\" height=\"14\" viewbox=\"0 0 14 14\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath class=\"vertical\" d=\"M2.75 7H11.25\" stroke=\"currentColor\" stroke-width=\"var(--icon-stroke-width)\" stroke-linecap=\"round\"\u003e\u003c\/path\u003e\u003cpath class=\"horizontal\" d=\"M7 2.75L7 11.25\" stroke=\"currentColor\" stroke-width=\"var(--icon-stroke-width)\" stroke-linecap=\"round\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/span\u003e\u003c\/summary\u003e\n\u003cdiv class=\"details-content rte\"\u003e\n\u003ctable class=\"custom-specs-table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eEFI System\u003c\/th\u003e\n\u003cth\u003eCompatibility\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHolley Avenger EFI\u003c\/td\u003e\n\u003ctd\u003eCompatible\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHolley HP EFI\u003c\/td\u003e\n\u003ctd\u003eRequired\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHolley Dominator EFI\u003c\/td\u003e\n\u003ctd\u003eRequired\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eUniversal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eFitment Notes\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eRequired for Holley HP EFI and Dominator EFI ECU installations.\u003c\/li\u003e\n\u003cli\u003eCompatible with Holley Avenger EFI systems.\u003c\/li\u003e\n\u003cli\u003eThe harness must be connected directly to the battery terminals.\u003c\/li\u003e\n\u003cli\u003eDo not connect the harness to a battery disconnect switch, starter solenoid, power distribution stud, or other intermediate power source.\u003c\/li\u003e\n\u003cli\u003eIf additional length is required, Holley recommends extending the harness using 8 AWG or larger multi-strand wire.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003chr\u003e\n\u003cdetails class=\"details\"\u003e\n\u003csummary\u003e\u003cstrong\u003eFAQ\u003c\/strong\u003e\u003cspan class=\"svg-wrapper icon-plus\"\u003e\u003csvg width=\"14\" height=\"14\" viewbox=\"0 0 14 14\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"\u003e\u003cpath class=\"vertical\" d=\"M2.75 7H11.25\" stroke=\"currentColor\" stroke-width=\"var(--icon-stroke-width)\" stroke-linecap=\"round\"\u003e\u003c\/path\u003e\u003cpath class=\"horizontal\" d=\"M7 2.75L7 11.25\" stroke=\"currentColor\" stroke-width=\"var(--icon-stroke-width)\" stroke-linecap=\"round\"\u003e\u003c\/path\u003e\u003c\/svg\u003e\u003c\/span\u003e\u003c\/summary\u003e\n\u003cdiv class=\"details-content rte\"\u003e\n\u003ch3\u003e1. Why must this harness connect directly to the battery?\u003c\/h3\u003e\n\u003cp\u003eHolley specifies a direct battery connection to ensure the ECU receives clean, stable voltage without interference or voltage drop caused by disconnect switches, starter solenoids, or power distribution blocks.\u003c\/p\u003e\n\u003ch3\u003e2. Why is 10 AWG wire used?\u003c\/h3\u003e\n\u003cp\u003eThe heavy-duty 10 AWG Automotive TXL wire is designed to safely carry the current required by Holley EFI systems while minimizing voltage loss over the harness's 13-foot length.\u003c\/p\u003e\n\u003ch3\u003e3. Can this harness be extended?\u003c\/h3\u003e\n\u003cp\u003eYes. If additional length is required, Holley recommends extending the wiring using 8 AWG or larger multi-strand wire to maintain proper current capacity and minimize voltage drop.\u003c\/p\u003e\n\u003ch3\u003e4. What is the purpose of the braided split loom?\u003c\/h3\u003e\n\u003cp\u003eThe braided split loom protects the wiring from abrasion, vibration, and heat commonly encountered in automotive, racing, and off-road environments while allowing easy routing through the engine compartment.\u003c\/p\u003e\n\u003ch3\u003e5. Is this harness fused?\u003c\/h3\u003e\n\u003cp\u003eYes. The harness includes integrated 40-amp fuse protection to help safeguard the EFI power circuit against electrical faults while providing reliable battery power to the engine management system.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003c\/details\u003e\n\u003chr\u003e","brand":"Holley","offers":[{"title":"Default Title","offer_id":56886391144614,"sku":"558-308","price":110.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0693\/8394\/6406\/files\/558-308-Holley-EFI-Main-Power-Harness-1.jpg?v=1785441371","url":"https:\/\/wideopendesign.com\/products\/holley-efi-main-power-harness-for-avenger-hp-dominator-efi-13-ft","provider":"Wide Open Design","version":"1.0","type":"link"}