Yes they can, as long as you wire them into the turn signals using the supplied parts. The bike: black to black, Brown to yellow is the 12v turn, the other wire is the 12v, (on my US bike) no guarantees...
Install was typical for me, only needed one trip for a pan head SS I stripped, they mount to the outside deflector which makes getting the nuts very hard to get to... I almost through bolted them, but take your time and do it right.