1. Battery and Electrical System:
* Dead or Weak Battery: This is the most common cause. Test the battery voltage with a multimeter. It should read around 12.6 volts when fully charged. Less than 12 volts indicates a weak battery. Have the battery load tested at an auto parts store to determine its health.
* Loose or Corroded Battery Terminals: Clean the terminals with a wire brush and baking soda solution. Make sure they are securely connected.
* Alternator Issues: A faulty alternator won't charge the battery, leading to starting problems. Have the alternator tested.
* Starter Motor Problems: A failing starter motor might be slow to crank or not crank at all. This often requires professional diagnosis and repair.
* Wiring Problems: Check for any loose, damaged, or corroded wires in the starting circuit. This can be difficult to diagnose without some electrical knowledge.
* Security System Issues: If the car has a factory alarm or aftermarket security system, a malfunction could prevent the car from starting. Check the key fob battery and try any keyless entry remotes.
2. Fuel System:
* Empty or Low Fuel: Sounds obvious, but worth checking!
* Fuel Pump Failure: A faulty fuel pump won't deliver fuel to the engine. You might hear a humming sound from the fuel pump when you turn the key to the "on" position (but not cranking). If not, this is a suspect.
* Clogged Fuel Filter: A clogged filter restricts fuel flow.
* Fuel Injectors: Problems with fuel injectors can prevent the engine from getting the fuel it needs to start.
3. Ignition System:
* Ignition Switch: A faulty ignition switch can prevent power from reaching the starter motor or other components.
* Ignition Coil: A bad ignition coil won't provide the necessary spark to ignite the fuel-air mixture.
* Spark Plugs and Wires: Worn or damaged spark plugs or wires can prevent proper ignition.
Troubleshooting Steps:
1. Check the obvious: Battery voltage, fuel level.
2. Listen carefully: When you turn the key, do you hear any clicking, whirring, or humming sounds? This can help pinpoint the problem.
3. Visual inspection: Check for any obvious signs of damage to wires, connectors, or components.
4. Consult a repair manual: A repair manual specific to your 2002 Chrysler Concorde LXi will provide detailed diagrams and troubleshooting steps.
5. Seek professional help: If you're not comfortable working on your car's electrical system, take it to a qualified mechanic.
Without more information about the symptoms (e.g., does it crank but not start? Does it make any unusual noises? Does the security light flash?), it's impossible to give a definitive diagnosis. Provide more details, and I can offer more specific advice.
