Electrical Issues:
* Battery Connections: Loose, corroded, or dirty battery terminals are a very common cause of intermittent starting problems. Clean and tighten them thoroughly. Check the battery cables themselves for internal breaks or corrosion.
* Battery itself: A weak battery might have enough power for some starts but not others, especially in cold weather. Get the battery load tested.
* Wiring: Look for damaged, frayed, or corroded wiring in the starter circuit. This includes the wires leading from the battery, through the ignition switch, and to the starter solenoid. Pay close attention to the connections at the solenoid. A bad ground connection is another frequent problem.
* Starter Solenoid: The solenoid is the "switch" that activates the starter motor. It might be sticking, have internal issues, or have a weak pull-in. You can test it with a multimeter. Sometimes a tap on it will temporarily fix it, indicating a problem.
* Ignition Switch (again): While you replaced it, ensure the new switch is correctly installed and all connections are secure. A faulty new switch is possible, though less likely.
* Neutral Safety Switch: This switch prevents starting unless the transmission is in park or neutral. A faulty switch can cause intermittent starting problems. Test its continuity in each gear position.
* Wiring harness connectors: These can get corroded or lose connection over time. Carefully examine all connectors in the system.
Starter Motor Issues:
* Starter Motor itself: Even with new parts elsewhere, the starter motor might have internal problems like worn brushes, a failing armature, or a short in the windings. A shop can test it.
* Bendex Gear: Even though you replaced the over-ride, there might be other issues with the Bendix gear (the mechanism that engages the flywheel). It could be binding, sticking or worn.
Other Possibilities:
* Loose ground straps: Check the ground straps from the engine to the chassis and the battery to the chassis. A poor ground can cause all sorts of electrical gremlins.
Troubleshooting Steps:
1. Start with the basics: Clean battery terminals, tighten all connections, and visually inspect all wiring.
2. Test the battery: Have it load tested at an auto parts store.
3. Check the voltage at the battery terminals during cranking: This tells you if the battery and charging system are functioning correctly.
4. Test the starter solenoid: Use a multimeter to check for continuity and power at the solenoid terminals.
5. Test the neutral safety switch: Check continuity in all gear positions.
6. Inspect the starter motor visually: Look for any obvious signs of damage or wear.
7. If all else fails: Have a mechanic or auto electric shop test the starter motor, and the entire starting circuit for shorts, breaks, or bad grounds. They have specialized equipment for this.
Remember to always disconnect the negative battery terminal before working on any electrical components. Safety first!
