I run a repair shop in new mexico but im no expert on the Pajero Ive never seen one seeing how they were never sold in the U.S. but they have a dual battery set up? and you jump one battery to the other and it starts, that sounds like you have a bad connection beetween the batteries and the one doing all the work is going bad. Check your battery connections and see if they are corroded the black and grey corossion they get on them is just as bad as the white build up they get. If you can get your hands on a volt meter with the vehicle running check voltage at each battery, should be 13.5 to 14.5 volts. That would tell you if your alternator is working. And if there is a significant voltage difference between batteries you would have a bad connection. Hope this helps.