LS SWAPS: Wiring Harness and Wiring Guide - LS Engine DIY Mar 10, 2015Some LS wiring harnesses include the underhood fuse box. Bolt this down in a convenient location. If you are using an aftermarket harness without a fuse box, make sure that the power wires are properly fused. (Photo Courtesy Street & Performance)Author: LS Engine Diy Moving the Coil Packs on an LS Engine - Hot Rod Network Jan 12, 2015Most wiring harnesses are designed to mate to the coil pack atop the valve covers and are routed so. Moving the coil pack requires lengthening the coil harness, made possible by Painless..