Wiring Harnesses & Modifications, Custom Made to Order for Hand-wired custom harnesses for guitars and basses. Tailor your harness to your unique preferences! We offer many style and upgrade options as well as typical replacements in standard and left-handed made-to-order wire harness versions. WIRING HARNESS and PREWIRED KITS - Arty's Custom Guitars Guitar Wiring HARNESS, Arty's Relic Custom Guitars, VARIABLE TREBLE BLEED.. We at Arty's Custom Guitars have specialized in the inner values of your favorites. For several years we have been building very high quality Wiring Harness for electric Guitars and Basses.