Has anyone had similar problem. This has happened 4 times. Hit the keyfob to unlock car. Get in, put key in ignition (if door is still open I get the dinging sound that the key is in the ignition), turn key, absolutely nothing. Now nothing works, radio, lights, door locks won't operate even with the keyfob. Attach jumper cables to battery, touch other end of cables together to get a spark. Put cables away, get in & start the Jeep. This is a very intermittent problem, 4 times in last 2 months. 48K miles & never had a problem in the past. Looking for any advice/suggestions you can give me before I take it to my mechanic.