by changing load its terminal voltage changes.
battery is low charge. Take it for a long drive, to take the load off the engine from the alternator charging it.
changing alternator belt on vauxhall corsa
change in voltage from no load to full load
Check fusable links
load demand
what is normal price alternator and labor
inside the alternator. check the fusable link at the alternator and at the starter before changing the alternator.
Because in the leading load or capacitive load the armature reaction is magnetizing.Here the stator flux adds up rotor flux and so the net flux of alternator increases and the net flux produces alternator's voltage.Hence the alternator's voltage rises.
by changing the alternator
Changing the alternator or removing and installing the belt should not cause excessive stress or wear on the belts.
Is it charging, if not have you checked wiring to alternator.
A changing load.