Hi! I have a 96 Grand Cherokee Limited with 5.2 V8 engine, I have problem that the car can start with Jump start, when I plug in the jumper cable or battery booster it can run, but when I unplug the cable it will shut down in one minute, I changed the alternator but it still happens, don't know why, the battery tested have no problem, please help me thanks

 

Welcome to CF!

Test the voltage at the PDC (fuse/relay box under the hood, fat red wire going into it) and see if your battery cables are actually supplying power to the system. Also, check your ground. You may have a bad battery cable or battery clamp.

That red wire supplies power to everything but the starter and a serious voltage drop in it will cause the ASD relay to drop out and shut down the engine.