* Bad Ground Connection: This is the most common cause. Even with new cables, a corroded or loose ground connection somewhere in the system will prevent sufficient current from flowing to the starter. Check:
* Battery ground cable: Make sure it's securely fastened to both the battery and the engine block. Clean both contact points with a wire brush.
* Engine block ground: Trace the ground straps from the engine block to the chassis. Look for corrosion, loose connections, or broken straps. Clean and tighten all connections.
* Chassis ground: Look for ground points on the frame near the battery and starter.
* Starter Motor Issues (despite being new): While you've replaced the starter, there's a small chance it's faulty or not properly installed.
* Wiring to the starter: Carefully inspect the wiring harness leading to the starter for any breaks, chafing, or loose connections. A poor connection here would cause the relay to click but the starter won't crank.
* Bendex gear (if the starter is a traditional one): This part engages the flywheel. If it's worn or damaged, it won't turn the engine, leading to the clicking. (Less likely if the starter is truly new)
* Voltage Drop: Even with a new battery, a significant voltage drop somewhere in the circuit can prevent the starter from receiving enough power. Use a voltmeter to check the voltage at the battery terminals, then at the starter motor's terminals while cranking. A significant drop (more than a volt or two) indicates a problem in the wiring or connections.
* Faulty Neutral Safety Switch (NSS): This switch prevents starting unless the transmission is in park or neutral. A faulty NSS will prevent the starter circuit from completing. Test the switch with an ohmmeter according to a wiring diagram.
* Ignition Switch: Though less likely given the clicking relay, a faulty ignition switch could be preventing the full 12V from reaching the starter circuit.
Troubleshooting Steps:
1. Check all ground connections FIRST. This is the most likely solution.
2. Voltage drop test: Measure the voltage at the battery and at the starter while cranking.
3. Inspect all wiring: Look for any signs of damage or loose connections between the battery, relay, and starter.
4. Test the neutral safety switch.
5. If all else fails, have a qualified mechanic diagnose the problem. They have specialized tools and experience to pinpoint the issue more quickly.
Remember safety first! Disconnect the negative battery terminal before working on any electrical components. If you're uncomfortable working with automotive electrical systems, seek professional help.
