The Trailblazer is a sport utility vehicle (SUV) manufactured by Chevrolet between 2002 and 2009. If your vehicle won't start, check a few simple areas before hiring a mechanic.
One reason your Chevrolet Trailblazer may not be starting is that the battery is drained. A battery can be drained in as little as one night by factors ranging from forgetting to turn the headlights off to leaving an interior light on overnight. A faulty alternator can also cease charging the battery, causing it to drain during normal operation.
If the battery seems to be in working order, the fuel system may be the cause of your Trailblazer problems. Ensure the vehicle has enough fresh fuel for operation. Old fuel in the system is subject to temperature fluctuations that cause water to condensate and collect in the tank. This water can cause the engine to shut off or not start altogether.
If your Trailblazer engine has a rattle, pop, bang or other noise audible during normal operation, it may be best to take your it to a professional mechanic. Diagnosing this type of problem can be difficult and time-consuming for amateur automotive enthusiasts.