1. Electrical System:
* Battery: Is the battery fully charged? Use a multimeter to check the voltage. It should be around 12.6 volts when fully charged. If it's low, charge it or replace it. Also check the battery terminals for corrosion and clean them if necessary.
* Starter: When you turn the key, do you hear a click, a whirring sound, or nothing at all?
* Click: This could indicate a weak battery, a bad starter solenoid, or a bad starter motor.
* Whirring: This might mean the starter is engaging but not turning the engine over. It could still be a weak battery or a seized engine.
* Nothing: Check the battery connections, the starter relay (if it has one), and the ignition switch.
* Ignition Switch: Is the ignition switch functioning correctly? Try wiggling the key while turning it. A faulty ignition switch can prevent power from reaching the starter.
* Wiring: Check all the wiring connections related to the starting system for corrosion or loose connections.
2. Fuel System:
* Fuel: Is there fuel in the tank? Check the fuel gauge and even consider adding some fuel to be sure.
* Fuel Pump: Can you hear the fuel pump prime when you turn the key to the "on" position (but not start)? If not, it might be faulty.
* Fuel Filter: A clogged fuel filter can prevent fuel from reaching the engine.
* Fuel Lines: Check for leaks or blockages in the fuel lines.
3. Engine:
* Distributor (if applicable): If the engine turns over but doesn't start, check the distributor cap and rotor for wear or damage.
* Spark Plugs and Wires: Worn or faulty spark plugs or wires can prevent the engine from igniting the fuel-air mixture. Inspect them for damage or corrosion.
* Carburetor (if applicable): If it has a carburetor, it might need cleaning or rebuilding.
* Engine Seized: If the engine doesn't even turn over, it might be seized due to lack of lubrication or other mechanical issues. This is a more serious problem.
Troubleshooting Steps:
1. Start with the easiest checks: Battery voltage, fuel level, and obvious visual inspections of wires and connections.
2. Listen carefully: The sounds you hear when turning the key (or lack thereof) will give you important clues.
3. Use a multimeter: This tool is essential for testing battery voltage and checking for power at various points in the electrical system.
4. Consult a repair manual: A repair manual specific to your 1986 Jeep Wagoneer will provide detailed diagrams and troubleshooting guides.
If you're not comfortable working on your vehicle yourself, it's best to take it to a mechanic. Giving them this information will help them diagnose the problem more efficiently. Remember safety first – disconnect the battery negative terminal before working on any electrical components.
