yeah i remember this post...his alternator was dying...then replaced his alternator with a 2001 Highlander's ALT. problem solved.
Highlander V6 3.0L engines are 1MZ-Fe...same engine code as the 3.0L V6 used in the camry since... edit '94... same engine code just different dimensions for a different chassis.
you have to have the 1MZ-Fe V6 in your camry for this to work. your dealer is telling you NO because in a way their just covering their asses, to them putting a part from one car into a different car doesn't jive. i would order the part and go to a different mechanic/garage to get it installed.
*here's the original post click here> HIGHLANDER 130 AMP UPGRADE