Possible Causes:
* Parasitic Drain: This is the most likely culprit. Something in your car's electrical system is drawing power even when the car is off, slowly draining the battery. This could be anything from a faulty interior light, a malfunctioning radio, a short circuit in the wiring, or even a failing alternator (though a failing alternator usually manifests differently).
* Faulty Ignition Switch: A malfunctioning ignition switch is a strong possibility given the key is stuck. It might be mechanically jammed, or an internal electrical component is failing, causing a constant drain and preventing the key from releasing.
* Security System Issues: The car's security system could be malfunctioning, causing a continuous drain or preventing the ignition from releasing.
* Alternator Problem (Less Likely, but Possible): While a constantly dying battery usually points to a drain, a failing alternator *could* contribute if it's not charging the battery properly, even if it's slightly working.
* Bad Battery (Less Likely, but Possible): While it's unlikely the battery is the *root* cause, a very old or severely degraded battery could have an internal short that exacerbates other problems.
Troubleshooting Steps:
1. Jump Start (If Possible): If you can get a jump start, try it. This will allow you to determine if the key is *only* stuck because of the dead battery, or if there's a deeper issue. If the key remains stuck after a jump, the battery isn't the primary problem.
2. Disconnect the Battery: With the car off, disconnect the negative (-) terminal of your battery. This will stop any parasitic drain. *Important: Leave it disconnected for at least an hour, preferably overnight, to see if the drain is significantly reduced.*
3. Check for Parasitic Drain (Requires a Multimeter): After disconnecting the battery, reconnect only the negative terminal. Use a multimeter to check the current draw. The reading should be very low, ideally under 50 milliamps (mA). If the reading is higher, there is a parasitic drain and you need to systematically disconnect fuses one by one to find the culprit circuit. This often requires electrical knowledge or professional help.
4. Try the Key: After disconnecting and reconnecting the battery (even if you didn't find a parasitic drain), try the key again to see if it releases.
5. Professional Help: If you can't free the key or identify the parasitic drain, take your Grand Prix to a qualified mechanic or auto electrician. They have the tools and expertise to diagnose and fix the problem. This situation could be more serious than a simple dead battery.
Important Considerations:
* Safety: Always disconnect the negative (-) terminal first when working on your car's electrical system to prevent shorts and injuries.
* Don't force the key: Forcing the key could damage the ignition switch further.
The key being stuck is a strong indicator that the problem is more complex than just a dead battery. Ignoring this could lead to further damage. Professional help is advisable.
