Genuine OEM Mazda Wiring Harness Door Front Left, part number BESL67190B. This wiring harness is responsible for transmitting electrical signals and power to and from the various components located within the front left door, such as power windows, locks, and speakers. It connects to the vehicle's main electrical system. Genuine Mazda harnesses are built with specific wire gauges, insulation, and connector types to ensure reliable and safe electrical function.