1967 mustang wiring harness | eBay Find great deals on eBay for 1967 mustang wiring harness. Shop with confidence. Skip to main content. eBay Logo: American Auto Wire 1967 1968 Ford Mustang Wiring Harness Kit # 510055 See more like this. 1967 Mustang Fastback Coupe GT Convertible ORIG UNDER DASH WIRING HARNESS woTACH. Pre-Owned. $599. 1967 Mustang Wiring Harness | eBay Part # 20121. Painless Wiring. This 22 circuit direct fit 1967-1968 Mustang harness has many of the factory connectors already installed on the harness out of the box.