Sorry if this is an obvious question, but does the V500 have a header to connect the the HDD LED on the front of the case (in my instance, of an A2000)?
As TuKo wrote, the Vampire itself doesn't have a separate LED header. But the signal you're looking for is available on the IDE. I routed the activity indicator to my A500 floppy light (which flashes for Floppy and CF now) as shown in the pictures below:
Electronics-wise, the adapter is easy. I just duplicated the _MTR0 path with two resistors and a PNP-Transistor. The collector of the transistor then goes to Pin8 of the keyboard connector.