A stock Chevrolet Silverado 1500 is designed to tow from a ball hitch mounted on the bumper, or from a larger hitch mounted underneath the bumper. But once the trailer is connected, it still needs to be wired to the brake lights on the Silverado, otherwise you risk getting into an accident. Although Chevrolet has provided an output for a trailer harness, you still need a specific adapter to be able to connect your factory harness to the trailer. Installing one takes about 10 minutes.
Crawl underneath the Silverado. Locate the stock wiring harness end, which is above the spare tire. Pull the stock harness out from the spare tire area with your hands.
Pull off the cap on the factory wiring harness by depressing the tab with your thumb and pulling off the cap. Secure the trailer wiring harness mounting bracket into the bottom of the bumper with the self tapping screws and a drill. Run the trailer wiring harness through the bracket, then bolt the end to the bracket with an flathead screwdriver.
Plug the factory harness into the trailer wiring harness. Zip tie any excess wiring to the hitch.
Test the lights to ensure they work properly, prior to taking the trailer out on the road.
