i just bought a 93 jeep grand cherokee 270k miles for 500 bucks but it ran... well for a few days the guy told me that the tcm is out so been trying to find one of those but he said the battery was bad and it was so i took it to walmart and it was driving ok when i got there after he changed the battery it started up faster i had to hold the key in for a bit before it would start before but it would still start but after the battery it started and then it would die after 2 seconds put old battery back in same thing put new battery in and pushed it to a parking spot now it wont even turn over just cranks i went and put gas in the tank and still got nothing not sure where to start the guy at walmart was thinking starter or altenator but idk only had the car 3 days and really havent driven it much

 

The guy said the tcm was out? Could he maybe have said the PCM or ECM instead of tcm?
Try giving the connectors at the PCM a good wiggle or even tapping on the PCM itself and give it a crank.

 

It sounds like you have an Anti Theft Security System. (You really should get an owner's manual.) When you disconnect the battery, and reconnect it, or install a new one, your anti theft security system will automatically disable the vehicle from starting and being driven. If you have a remote lock/unlock key fob ("keyless entry"), you can use it to disarm the security system. I'm not sure exactly what your specific model and year requires to disarm it without the keyless entry, but you may try locking and unlocking the rear lift door to see if that does it.

 

Longest run on sentence in history. I think Lady in Red nailed it, give it a shot.

 

If the lady in red is right then try locking and then unlocking the drivers door with the key. That's how my 94 zj will shut off the antitheft. It may be similar in your 93.

 

Lock and unlock rear hatch or PASSANGERS door, dont know why, but wont work from drivers side. The first time I replaced the battery in my 94 zj it did the same thing, drove me insane.

 

Also, as a semi related FYI...keys they make a walmart, Lowes, Home Depot etc are all thicker..and won't work in the tailgate. pain in the *** if you don't have the remote locks or they are dead...or have dead batteries.

I had to go to a locksmith to get a basic looking key, otherwise it is too fat to go in the tailgate keyhole.

And ditto to disarming with the hatch or passenger door.