I've read all the problems everyone else is having, and I'm having similar problems with my 1994 Grand Cherokee Laredo. I bought it about a year ago for about $1500 and the guy had really messed with the wiring, and when I installed a new stereo into it I had plenty of trouble deciphering what he had done.
While away at school my father tried to fix it, only to make it worse. It started with the security system going off on its own without making a sound, and killing the battery. I ended up having to buy a brand new battery, only to find that a short time after my truck wouldn't even start. In the semi-start position, the power goes on and the gauges come up, but there is no turnover, nor a sound with the ignition. I'm trying to avoid the costly trip to a specialist only to come up with the same answer most people got, especially cuz ive already put so much money into it, and i only spent about $1500 on it a year ago.
If anyone has a suggestion for where i should even start, an email would be much appreciated.