2004 ford focus wiring harness | eBay Find great deals on eBay for 2004 ford focus wiring harness. Shop with confidence. Skip to main content. eBay Logo: Shop by category. Shop by category. Enter your search keyword 04 2004 Ford Focus Engine Injector Wire Wiring Harness 3S4T-9h589-BAA See more like this. SPONSORED. 2004 Ford Focus OE Wiring Harnesses & Stereo Adapters Ford Focus 2004, Factory Replacement Wiring Harness by Metra®, with OEM Radio Plug. For factory stereo. This high-quality Metra wiring harness is just what you need to replace your defective or aged factory wiring harness.