Here's a breakdown of possible causes and what you should do:
* Faulty Ignition Switch: This is the most likely culprit. The switch itself might be worn, broken, or have internal electrical issues preventing it from fully returning to the "off" position. Replacement is usually necessary.
* Shift Interlock Mechanism: This system prevents the car from starting unless it's in park. A problem here could be causing the key to remain stuck. This might be a faulty sensor, a linkage issue, or even just a problem with the park position itself (e.g., transmission fluid low, worn linkage).
* Steering Wheel Lock: While less likely, a problem with the steering wheel lock mechanism could be contributing to the issue. It's possible the lock is partially engaged, interfering with the key's ability to fully disengage.
* Wiring Issues: Damaged or corroded wiring related to the ignition system or shift interlock could also play a role.
What you should do:
1. Safety First: Don't attempt any repairs while the key is still in the "on" position. This could drain your battery and potentially cause other electrical issues.
2. Try Jiggling the Shifter: Gently rock the shifter back and forth in the park position. Sometimes a slight adjustment can resolve a minor linkage problem.
3. Battery Disconnect: If you're comfortable with basic car maintenance, disconnecting the negative battery terminal for a few minutes might help reset the system (but won't fix the underlying problem). Reconnect the battery after waiting.
4. Professional Help: Given the symptoms, it's highly recommended to take your Trailblazer to a qualified mechanic or dealership. They have the diagnostic tools and expertise to pinpoint the exact cause and make the necessary repairs safely and correctly. Trying to fix this yourself without proper knowledge could potentially cause more damage or create a safety hazard.
Ignoring this issue could lead to a completely dead battery, or even further damage to your ignition system. It's best to address it promptly.
