2004 Chevrolet Impala wiring harness | eBay Find great deals on eBay for 2004 Chevrolet Impala wiring harness. Shop with confidence. 2004 Chevy Impala OE Wiring Harnesses & Stereo Adapters Chevy Impala 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.