The best way to check for ignition system problems on your Chrysler Town & Country depends on the type of system it has. Newer models have a system constructed without a distributor, meaning there are fewer parts you can and should check yourself. Test the spark plugs, Powertrain Control Circuit, crankshaft sensor and ignition coils.
Remove a spark plug from the Chrysler's engine (start with the No. 1 spark plug on a distributorless system). Examine the plug for cracks in its insulation. Replace it if necessary.
Connect the plug to its spark plug wire (use a fresh plug on a distributorless system). Ground the plug's outer electrode to a metal piece on the engine. Crank the engine and look for a strong spark across the electrodes.
Repeat for all the remaining cylinders. The ignition system is functioning properly if a strong blue spark exists across all plugs. Test the coil if one or more plugs show an irregular or weak spark, or no spark at all.
Check the distributor if no spark exists. Remove the distributor cap and make sure the rotor is turning when you crank the engine.
Test the spark plug wires. Disengage each wire on at a time while the engine idles to see if the engine's performance changes or not. Check each plug and the wire's resistance if the performance doesn't change.
Perform the failure-to-start test if no sparks appear on a distributorless system.
Use a Digital Volt/Ohmmeter to measure the voltage from the negative to positive battery terminals. It must be at least 12.66 volts to accurately inspect the system.
Detach the ignition coil's harness connector. Connect a suitable test light to the B+ terminal on the coil's electrical connector and to its ground. Don't spread the terminal with the test light probe.
Turn the ignition key to the "On" position. If the test light momentarily flashes, leave the ignition key on and continue testing the Powertrain module in Step 4. If the test light doesn't flash, assume the problem is the relay or a relay circuit.
Crank the engine to check if the PCM isn't receiving a crankshaft position sensor signal. If the light doesn't flash, move onto the crankshaft sensor in Step 5. If the light flashes, verify there's a problem by testing the sensor and related circuitry with a DRB scan tool.
Unplug the crankshaft position sensor connector. Turn the key to the "Off" position then back on. Wait for the test light to flash and crank the engine. The crankshaft position sensor must be replaced if the light flashes; move onto Step 6 if it doesn't.
Scan the engine with the scan tool, looking for a problem in the camshaft position sensor or related circuitry.
Wait for your Town & Country's engine to cool, or you may get an inaccurate measurement. Unplug the electrical connector from the ignition coil pack.
Connect an ohmmeter between the coil's B+ pin and the pin corresponding to the cylinders you're testing. Measure each coil's primary resistance, which should be 0.45 to 0.65 ohms at 70 to 80 degrees F.
Disconnect the spark plug wires from the coil's secondary towers. Measure the secondary resistance of the coil between the towers with the ohmmeter. The secondary resistance should be between 10,900 and 14,700 ohms.
Replace the coil if either test doesn't meet specifications.
