2003 liberty with new battery alternator tested good. Can charge battery and run it about 15 minutes the battery light will come on.The power will eventually diminish to point where it doesn't run. I tried pushing the 2 wire plug at back of alternator in and that seemed to fix problem, for a moment at least.

There is a voltage regulator fuse, check and make sure that fuse hasn't popped. The fuse should be located inside the car. Good luck

Jeep has been having massive wiring prob’s . With no end in sight most people are trading the off for another brand . If you find your prob, there will be more to come it gets expensive… trade it off.