* Dead Battery: The most common cause. The oil light may have been a warning sign of an issue that eventually drained the battery (e.g., a failing alternator). The clicking sound is the starter motor trying to engage but not having enough juice.
* Failing Alternator: The alternator charges the battery while the engine is running. If it's failing, it might not have been charging the battery properly, leading to a drained battery, and the oil light could have been unrelated (though low oil pressure *can* sometimes stress the alternator).
* Bad Battery Cables or Connections: Corrosion or loose connections on the battery terminals can prevent sufficient power from reaching the starter motor. This would also result in a clicking sound.
* Starter Motor Issues (Less Likely): While a faulty starter motor is possible, it's less likely to be the *sole* cause given the oil light warning. A failing starter would usually result in a clicking sound even with a fully charged battery, but the oil light suggests another underlying problem likely contributed to the battery drain.
What to do:
1. Check the battery terminals: Look for corrosion (green or white buildup) and tighten any loose connections. Clean the terminals with a wire brush if necessary.
2. Try jump-starting the car: If you can get a jump, this will help determine if the battery is the primary issue. If it starts and runs, the problem is likely a dead battery or alternator. If it still only clicks, the problem might be more serious.
3. Call a tow truck or roadside assistance: If you can't jump start the car, or if you suspect a more serious mechanical issue (especially given the oil light), it's best to have a professional diagnose the problem. Driving with low oil pressure can cause significant engine damage.
Do not keep trying to crank the engine repeatedly if it only clicks. This will further drain the battery.
