weak alternator issue

I did check. all is ok

I asked driver about peoblem and he told me that got this problem after truck was on customs for four days, batteries were low but started the engine so I sugest current stress

BTW, I've never seen armature damage, the only things that fail are bearings, brushes (on European trucks), diodes and voltage regulators. So IMO armature is stronger the diodes! So I'd upgrade diodes, but I try to find 100-200 amp diodes of small size.