yeah, but AC voltage not DC like in automotive.
so set your meter to AC before testing it.
if you look at your headlight switch there will be 2 wires running off that, down the bars and into the rubber boot/loom end behind the headlight.
unplug the 2 wires from the headlight switch in the boot, and test both of them for 6V-7V AC when the engine is running
you will only get power from one wire.
the other lead is the power feed that goes to the headlight bulb
while you have your meter out,
you can test the actual headlight switch,
grab the 2x wires that come from the switch
set your meter to 200 Ohms again put one lead to one terminal, and the other to the other terminal.
turn your switch to on, and you should get a reading on your meter.
if you get a 1 come up, then there is a problem in the switch.
there are a couple of brass contacts inside the switch, if they are corroded, or dirty then that could cause a bad contact.
spray them with wd40 etc, and give them a wipe off, and put the switch back together and retest it.
and, no both lights are both powered off the same circuit,
a blackend bulb shows that there's been too much voltage run through it.
most of the time if one globe blows it will spike the power and blow the other.
you can check your bulbs with your multimeter, set it to 200 Ohms,
your meter should read 1, now touch your leads together and it should read .1 or 2 (or close)
this shows you that there is a good circuit there, if it stays at 1, then you have a broken cicuit
if you get a 1 reading when testing a bulb, then it is usually the filament that has broken.
so place one lead to a terminal contact point on the bulb, and the other lead to the the bulb bases' metal housing.
you should get a reading say .8 or around that if the bulb is ok,
or it won't change, and will show a 1 if there is a broken filament
try the above tests out, and if you can't get a voltage reading from one of the wires coming from the switch, i'll let you know the Ohms reading that you can test for, from the Lighting coil in the stator
there is also another connector for the stator to the main wiring loom
it is located up above the carby, usually strapped to the frame