2003 Chevy Silverado 1500 HD Engine Wiring Harnesses

Looking to swap the venerable LS engine into your hot rod, muscle car, or classic truck? Take a look at our detailed identification guide for Gen III/IV LS engines before you hit the salvage yard or swap meet!

In this Tech Tip, John answers a customer question about the Speedway 12 Circuit Wiring Harness.

A guide on how to install a universal wiring harness in a car. Read tips on properly wiring taillights, headlights, gauges, ignition switch, steering column and more.

In this Tech Tip, a returning customer asks for advice on wiring harnesses for his ’29 Ford roadster project.

Unbox our most popular wiring harness with Tim.

Read how to wire a lightning sprint engine. This detailed account of how to successfully wire an engine will ensure a smooth installation.

Electrical wiring is one of those tasks that enthusiasts dread tackling on their own. We're here to tell you that wiring your project vehicle is something you can do with a little help from your friends at Speedway Motors!

Speedway Motors just added some exciting new options to our line of racing harnesses.

Take a look at a few of the rare and wonderful Chevy engines in the Museum of American Speed!

Watch our Steering Column Wiring Guide video for useful tips on wiring your new steering column for your vehicle. Ididit takes you through the wiring process.