Highway 15 Universal Wiring System - American Autowire Ample lengths of pre-labeled GXL wire make it simple to create custom routing specific to your needs. The Highway 15 is a brute in a small package. Built with the same heavy duty internal components as those used in our Highway 22 panel, it can easily handle the basic power requirements of any vehicle. American Autowire Highway 15 Wiring Harness Kits - Free 36 Customer Reviews. American Autowire Highway 15 wiring harness kits are powerful little brutes! Built with the same heavy-duty internal components as the Highway 22s, the small-size Highway 15 panel can easily handle the basic power requirement of your vehicle.