Our Mil-spec engine harness services begins with a complete disassembly of your donor harness, and a full electrical schematic of how the engine should be wired for your application. 

Then we measure all the correct wire lengths for a tucked harness (as far out of sight as possible), including any additions to the harness, like extra sensors, coilpacks, etc, and deleting anything we no longer need. We also take into account moving the firewall pass-through location, especially if using a Mil-spec bulkhead connector. Any stock connectors used will have the best Mil-spec 200*C silver-stranded tefzel wire soldered to the pigtails in staggered joints, and as it's going together, the harness is loomed with your choice of Mil-spec flame-retardant expandable mesh sleeving or Mil-spec high-performance heat shrink loom (Raychem DR25 equiv) with Mil-spec double-wall adhesive heat shrink on each end. Breakout boots are available on full heat-shrink loomed harnesses. The ECU connector is depinned of any unnecessary wires and any additional wiring brought into the cabin is terminated in your choice of connectors, from flying leads for the DIY'ers to the more popular Deutsch connectors, to Autosport Mil-spec connectors.