2004-silverado-switched-power-source Page
Open the front passenger door; the panel is on the end of the dash.
Finding Switched Power in a 2004 Chevy Silverado (Easy & Safe Methods) 2004-silverado-switched-power-source
There is often an unused relay socket (upper left) that provides 12V key-on power. Open the front passenger door; the panel is
Behind the plastic knee panel on the driver's side, near the parking brake mechanism, there is a relay block. Open the front passenger door
Look for a thick white wire in the ignition wiring harness.
If you need a "hard" switch that cuts power instantly when the key turns, check under the dash.