Q: Sputtering issues and voltage gauge reading 0 on the dash.

Hello. From what you describe it would appear that your vehicle is experiencing some sort of issue with the electrical system. If the alternator is not charging, even after being replaced, then it may be possible that there is an issue with the voltage regulator. The voltage regulator is the component that controls the charging and output capacity of the alternator. For many vehicles the voltage regulator is integrated into the alternator, however for your model of Grand Cherokee the voltage regulator is located inside of the PCM, that is the engine computer. For this reason, a fault with the voltage regulator usually requires replacement of the PCM. A test of the voltage regulator circuit would be required to determine if this may be the case. I would recommend having a professional technician, such as one from YourMechanic, come to your location to diagnose what is causing your charging system to malfunction.

Hi there. Check all of the wiring from the alternator to the battery and power source box (fuse box). Make sure that all of the connections are in the right place and make sure that the wires are not corroded. It is possible that the alternator you have is either not hooked up correctly or the alternator is not working properly. Have the alternator checked to see how much AC voltage is leaking out. If there is more than 30 AC voltage producing, then the diodes inside the alternator are burned. If you need further assistance with your engine sputtering when you have the alternator hooked up and then works fine with the alternator disconnected, then seek out a professional, such as one from Your Mechanic, to help you.