Most auto parts stores will scan and recommend replacement part at no charge
Inside the alternator.
it is in the alternator
If you are referring to the voltage after the rectifiers in a powersupply, it is due to the voltage drop across the rectifiers.
Phase, if you are referring to line, as power line from pole.
Trouble code P0562 means: System voltage low
replace the ignition module Its under the rotor inside the distributer cap
Easiest test is to use a voltmeter. Engine stopped , voltage about 12 volts Engine running, voltage about 14.7 volts.
A regulator is referring to a regulator rectifier which converts the ac voltage put out by the stator to dc voltage and regulates it to a consistent voltage usually 12-14 volts dc.
Trouble code P0137 means:O2 sensor circuit low voltage (Bank 1 Sensor 2)
get a scanner and check the datastream for the TPS sweep voltage or go to a qualified mechanic for a diagnostic
Trouble code P0562 means:System voltage low
P1682 Charging System Voltage Too Low