Wiring Harness for 5 or 5 EFI - Tom's Bronco Parts Description This 5 EFI Fuel Injection Wiring Harness is far and away the best quality and easiest installation fuel injection wiring harness for your Early Bronco or Classic Ford Truck. Designed to work with 89-93 Ford Mustang 5 or 5 EFI motors with Mass Air-Flow, simply lay this kit over the engine and connect the wires. Wiring Harness & Pigtails - Toms Bronco Parts If your Bronco's wiring is fried, Tom's Bronco Parts can help. We offer complete Centech body wiring harnesses, the most affordable, high quality & easy to use wiring harness on the market for early Broncos. If you just need to repair a small section of your wiring, we also offer a variety of replacement pigtails for common areas of concern.