Wiring Harnesses | Impalas - 1970 Wiring Harnesses If the wiring in your Chevy Impala is cracked, patched with electrical tape or has new wiring spliced in, it definitely needs to be replaced. You'll eventually have problems with burned out electrical equipment or even worse, an electrical fire. 1970 impala wiring harness | eBay Find great deals on eBay for 1970 impala wiring harness. Shop with confidence. Skip to main content. eBay Logo: For 1964-1974 Chevrolet Impala Firewall Wiring Harness Gutter 28521KB 1967 1970 See more like this. 1971-1975 GM 6-Way Power Front Seat Wiring Harness *NICE ORIGINAL* (Fits: 1970 Impala) Pre-Owned. $79.