alt. has no fuse on unit. The charging system is working for the first min. or so! but then it trips something , & the guage drops from a charge to no charge reading & light comes on! if i shut it off & restart, it will charge for the first part again ! and so on ........

ok what it sounds like is that the alt is causing a draw and there for either the computer is shutting it down out the ecu is bad and shutting down the charging side of the alt. there is also an auto shut down relay but if this goes off the whole jeep would shut down I believe. take the ALT down to a auto part store and have them do a draw test on it.