Car radio accessory switched 12v wire.
2006 power distribution schematics. They deleted the best image color coded wiring diagram of the 2004 trailblazer which i am almost certain is the same as your 2006.
2004 Trailblazer Wiper Wiring Diagram Wiring Diagram
Chevrolet Trailblazer Radio Wiring Wiring Diagram
Chevy Fuse Box Diagram Owner Manual Wiring Diagram
