How did we get to the ignition coil? I'm getting confused because I just posted an answer that did relate to that. You have the additional symptom of dead gauges. That points to something other than the common loss of spark, and the likely suspect is the ignition switch or its wiring. One clue to listen for is the hum of the fuel pump. You should hear it run for one second after turning on the ignition switch. If you don't, there's a power supply problem and it's most likely related to all of these things.
If you DO hear the pump run for one second, we know the automatic shutdown (ASD) relay is turning on. It must turn on again during engine rotation, (cranking or running). To test for that, measure the voltage feeding the ignition coil positive terminal, any injector, or either smaller terminal on the back of the alternator. You should find 12 volts there for that first one second, then again during cranking. On the cars that's a dark green / orange wire. I'm not sure if it's the same on Jeeps. The wire you're after will be the same color at all the points I mentioned.
Monday, August 11th, 2014 AT 12:49 AM