The 2005 Chevrolet Trailblazer has become notorious for having many widely reported complaints, as of 2015. The most common concern is failure of the vehicle's fuel gauge, mostly due to the failure of a fuel level sensor within the fuel tank. It is possible that GM could offer a contribution toward the repair cost dependent upon chassis number, so it would be worthwhile to check with a local Chevrolet agent to confirm this.
Other common complaints regarding the 2005 Chevy Trailblazer include failure of the instrument panel or speedometer, leading to the replacement of the panel assembly. Consumers also report the check engine warning lamp illuminating, problems with the stereo system, and numerous electrical problems.
The electrical problems include the doors locking by themselves, the ABS warning lamp illuminating, windshield wiper switch failure, dashboard oil gauge not working, and dash panel illumination failing. Headlamps can dim or brighten unexpectedly, flicker, or not work at all. Problems with the blower fan either stopping altogether or working on only certain speeds have also been reported.
Mechanically, not as many issues have been reported, and according to CarComplaints.com, there are relatively few issues with transmission failure. Steering and suspension problems appear to be fairly uncommon as well.
Overall, the 2005 Chevrolet Trailblazer does appear to have a large number of relatively common complaints, but lots of these complaints are well documented, and repair procedures appear to be fairly easy to obtain for the most common issues.