That would be a good place to start. If you think the ground is an issue, make your own ground lead.
There's also the possibility that your head unit is dying or dead. The easiest way to eliminate that possibility is to pull the radio out of the dash, take it over to your battery, and directly hook up power and ground to the battery. Make sure you hook up both power wires to positive, one is a constant power, the other is the keyed on power. If it still acts the same, your wiring isn't the problem.
My cylinder head overhaul: http://www.jeepforum.com/forum/f13/cylinder-head-r-r-picture-heavy-1348138/
My transmission overhaul: http://www.jeepforum.com/forum/f13/how-change-transmission-electronics-1560948/