There is a Chrysler spark plug for each cylinder in your engine. Each spark plug is sent an electrical impulse signal from the onboard computer on the newer models. On the older models, the spark plug receives a signal from the distributor. It does not really matter to just how your Chrysler spark plug receives it electrical charge, just as long as it generates a spark in the correct heat range at the right time that ultimately matters. The heat range is determined by the spark plug for your Chrysler engine. If the plug is too hot, it could burn a hole in the top of the piston which could make the rebuilding of the engine necessary. Obtaining the correct heat range for your replacement spark plug is done by only replacing this part with what is listed in the parts manual. Each manufacturer has a different specification, but can be cross referenced correctly. Testing the spark plug and the rest of the ignition system on your Chrysler engine can be completed by the owner of the car. This procedure requires a plug to be grounded out to the engine while the wire is connected to it and the engine turning over. A deep strong blue spark should be easily seen at the electrode of the plug. If this is not what is visible the first step would be to change the spark plug and repeat the test. If a blue spark is still not seen, replace the wire. The tracing backwards in the ignition system is how you can determine just what part is failing. So your Chrysler can have the ability to run efficiently and with maximum power the spark plug must be gapped correctly in the right heat range so the fuel will explode as expected.