* Dead or Weak Battery: This is the most common cause. A weak battery might have enough power to click the solenoid in the starter (the clicking sound), but not enough to actually crank the engine. Have the battery tested at an auto parts store – a load test is crucial, not just a voltage check.
* Loose or Corroded Battery Cables: Check the battery terminals and the cables connecting them to the battery and the starter. Look for corrosion (white powdery substance) and ensure the connections are tight and clean. Corrosion can severely restrict current flow.
* Faulty Battery Cable Connections: Even if the cables look good, the connections at the battery, starter, and engine block may be loose or corroded internally. Try cleaning them thoroughly, or replacing the cables entirely if they're suspect.
* Bad Solenoid (within the starter): While you've replaced the starter, it's *possible* the new starter has a faulty solenoid. Although less likely given you just installed it, it's worth considering if the other possibilities are ruled out.
* Faulty Ignition Switch: The ignition switch might be failing to send enough power to the starter.
* Bad Neutral Safety Switch (NSS): This switch prevents the car from starting unless it's in park or neutral. A faulty NSS will prevent the starter from receiving power.
* Low Voltage at the Starter: Use a voltmeter to check the voltage at the starter's terminals while someone tries to crank the engine. You should see 12V (or close to it). A significantly lower voltage indicates a problem in the wiring or connections between the battery and the starter.
Troubleshooting Steps:
1. Battery Test: This is the absolute first step. Get a load test, not just a voltage reading.
2. Cable Inspection: Visually inspect all battery cables for corrosion and tightness. Clean terminals thoroughly with a wire brush and baking soda solution.
3. Voltage Check at Starter: Measure voltage at the starter terminals during cranking.
4. Check all grounds: Make sure all ground connections to the engine block and chassis are clean and tight. Poor grounding can severely limit current flow.
If you've checked these and still have the problem, you'll likely need a mechanic or more advanced diagnostic tools to pinpoint the issue. Ignoring a clicking-only starter can lead to further damage to your battery and electrical system.
