2003 Trailblazer HVAC Schematic | GMTNation I've got a 2003 TB EXT with the typical actuator clicking/non-functioning problems in the rear. I've removed the rear panel to access the actuators, and remembered an old site that had the hvac schematic and part numbers for this truck. I went to that "old" site, and saw that there were issues and our beloved Roadie had moved over here. TrailBlazer | Trailblazer EXT - Car Forums and Automotive Chat Need help with 03 TB/LT/EXT Front axle/diff; Replacing the rack & pinion 2002 TB; New to the Trailblazer; accessory power outlet fuse? tailgate. Interior trim panel Removal; Power steering or rack and pinion? trailblazer no sound from rear door speakers; 2006 Trailblazer doesn't blow on speed 5; 2003 Trailblazer EXT; 2008 TB radiator drain 2003 Chevy Trailblazer Wiring Schematic PDF fileChevy Tail Light Wiring Diagram Chevy Tail Light Wiring. This kind of owners manual 2003 chevy trailblazer is often a very detailed document. 02 CHEVY TRAILBLAZER TRANSMISSION WIRING DIAGRAM. 2008 Chevy Silverado Wiring Diagram. Air Conditioner 2002 Chevy Trailblazer Radio Wiring Diagram. 2003 Ford Expedition Fuel Pump Relay Location.