One problem related to headlight switch has been reported for the 2003 Chevrolet Trailblazer. The most recently reported issues are listed below.
The contact owns a 2003 Chevrolet Trailblazer. While driving various speeds, the headlights suddenly shut off and later turned back on. The headlights on/off switch was replaced, but the failure continued. The vehicle was taken to a dealer, but the failure could not be duplicated. The manufacturer was notified of the failure. The failure mileage was 120,000.