1. The Basics:
* Battery: Test the battery voltage with a multimeter. It should read around 12.6V when fully charged. If low, charge it or replace it. Also check the battery terminals for corrosion – clean them if necessary.
* Cables: Inspect the battery cables for damage, looseness, or corrosion. Clean or replace as needed.
* Starter: Try to engage the starter directly (if you're comfortable doing so and know how – this involves bypassing the ignition switch). A clicking sound means a weak battery, bad cable connection, or a failing starter. No sound points to a starter motor issue, a bad connection to it, or something further up the electrical chain.
2. Ignition System:
* Ignition Switch: Try tapping the ignition switch lightly while someone tries to start it. A faulty switch can be intermittent.
* Distributor Cap and Rotor: Inspect the distributor cap and rotor for cracks, burns, or corrosion. Replace if necessary.
* Spark Plugs and Wires: Check the spark plugs for wear and fouling. Replace if necessary. Also, inspect the spark plug wires for cracks or damage.
* Ignition Coil: A faulty ignition coil won't produce a spark. Testing this requires a multimeter or a spark tester.
* Ignition Module (or Electronic Ignition Control Unit): These can fail and prevent sparking. These often need specific testing equipment.
3. Fuel System:
* Fuel Pump: Can you hear the fuel pump prime when you turn the key to the "on" position (but not cranking)? If not, it may be faulty.
* Fuel Filter: A clogged fuel filter will prevent fuel from reaching the engine. Replace it if it hasn't been done recently.
* Fuel Lines: Check for leaks, cracks, or kinks in the fuel lines.
* Carburetor (if equipped): If you have a carburetor, it might be clogged, flooded, or need adjustment. This is more complex and often requires carburetor cleaning or rebuilding.
4. Other Possibilities:
* Neutral Safety Switch (automatic transmission): The engine won't crank if the transmission isn't in park or neutral.
* Solenoid: The starter solenoid is the "relay" between the battery and the starter. A bad solenoid can prevent the starter from engaging.
* Wiring Issues: Damaged or corroded wiring can prevent power from reaching critical components.
* Security System (if equipped): Some CJ-5s had aftermarket security systems which could be disabling the start.
Troubleshooting Steps:
1. Start with the simple checks: Battery, cables, and visual inspection of components.
2. Listen for sounds: Clicking, whirring, or nothing at all can provide clues.
3. Check for spark: Use a spark tester or carefully test at the spark plug to see if you're getting spark.
4. Check for fuel: See if fuel is reaching the carburetor or fuel injectors.
Important Note: Working on a vehicle's electrical system can be dangerous. If you're not comfortable working on cars, take it to a mechanic. Always disconnect the negative battery cable before starting any work.
By systematically checking these areas, you should be able to pinpoint the cause of the problem. Remember to document your findings as you go through the process. Good luck!
