Wiring harnesses for classic Chevy trucks and GMC trucks Wiring harnesses, wiring harness clips, and obsolete parts for classic Chevy trucks and GMC trucks from Classic Parts of America. 73 chevy truck wiring harness | eBay Find great deals on eBay for 73 chevy truck wiring harness. Shop with confidence. Skip to main content. eBay Logo: 73-87 Chevy Gmc TRUCK, K5 BLAZER Power Window & Lock Door Wiring Harness oe. Pre-Owned. NOS 73-75 Chevy Truck Blazer Tach Wiring Harness OEM 8906031 GM 10 20 30 SK See more like this.