Lee was on the right track...
If you've got the 4.0L engine and 42RE transmission, there was a problem with these vehicles (which many indy shops don't know about) resulting in the premature coil failure you're describing. Most though had long ago been repaired under warranty. The fix is to install an upgraded coil and harness package, Chrysler part numbers 4762312 and 4762311, repsectively. Won't set you back too bad, both items should total around $115 list rom your local Chrysler dealer. Book time on the job is only 0.3 hours.
Basically, you'll be installing an upgraded low resistance coil, and a "jumper harness" which contains and external resistor like Lee described.
If you need detailed instructions on how to do this (they might be in the 4762311 harness pack, if I recall), I can step-by-step it for you. It's also good idea to disconnect the negative battery cable to "clear" the PCM.
Problem should then be solved. Does your A/C still work, the evaporators on those are high failure too.