Holley EFI Main Power Harness

  • Sale
  • Regular price $86.95

Fused main battery power harness for Holley HP, Dominator and Terminator X ECU's. Built in-house by Jolt Systems in custom lengths.

Is the battery mounted in the very back of your truck bed or land yacht? Save the pain of extending such a critical power harness with butt splices. Or at the other extreme, is your battery mounted up front on the floor board in your race car? Save the waste of cutting a universal harness down, while getting a cleaner install too!

Compare to Holley part no. 558-308.


  • Purpose-built length
  • Fuse is placed closer to battery end instead of ecu end for proper fusing protection.
  • Wrapped in a higher quality, lower profile woven loom.
  • Loom ends capped with heat shrink labels instead of tape.

What's in the Box

  • Main power harness
  • 3/8in ring terminals & heat shrink