2004-silverado-switched-power-source — Latest

There is often an unused relay socket (upper left) that provides 12V key-on power.

This circuit is often controlled by RAP (Retained Accessory Power), meaning it stays on for 10 minutes or until you open the door after turning off the key. 2. Under-Dash Relay Panel (Above Brake Pedal)

Unlike older trucks, the 2003-2006 Silverado/Sierra trucks (GMT800 platform) are heavily controlled by the CAN-bus system, meaning many fuses in the dashboard remain live (constant power) even after you turn off the truck. This can lead to parasitic battery drain and a dead battery! 2004-silverado-switched-power-source

Open the front passenger door; the panel is on the end of the dash.

For clean, safe tapping into the fuse box. There is often an unused relay socket (upper

This requires a bit more navigation than the fuse box. 3. Ignition Switch Harness

Look for a thick white wire in the ignition wiring harness. Under-Dash Relay Panel (Above Brake Pedal) Unlike older

Use a multimeter or test light to confirm it is hot only when the key is on. Essential Tools for the Job