Where is the stop light relay on a 2004 Chevy Silverado?

There isn't a single "stoplight relay" in the traditional sense on a 2004 Chevy Silverado (or most modern vehicles). The brake light function is controlled by the Body Control Module (BCM). The BCM receives the signal from the brake pedal switch and then sends the appropriate power to the brake lights.

Therefore, there's no separate relay to replace. If your brake lights aren't working, the problem likely lies with:

* Brake light switch: This is the most common culprit. It's located near the brake pedal.

* Fuses: Check the fuses related to the brake lights in the under-hood and interior fuse boxes.

* Wiring: Look for damaged or corroded wiring between the BCM, the brake light switch, and the lights themselves.

* Body Control Module (BCM): While less common, a faulty BCM can also cause brake light issues. This requires more advanced diagnostics.

* Brake lights themselves: Check the bulbs for burnout.

Instead of searching for a relay, start by checking the fuse and the brake light switch. If those are good, you'll need a multimeter or professional diagnostic help to further pinpoint the problem within the BCM or wiring.