So long as you can get a symbolic link, you can use a ritual to find a corpse- though that link would have to have been made after the target was a corpse. And in a similar way, you could use a tracking spell to find a BCV, but that would require a symbolic link made after the target was made into a vampire. And of course, there's the problems of warding and such.
Debunking Negative Assertions
I think that one of your assertions, i.e.
The reason I ask is I know that if you try to do a Tracking Spell for
a deceased mortal the spell doesn't work.
is making you make assumptions on the RAW that are not there.
Harry does have a tracking spell in the book, i.e. YS298 "Harry's Tracking Spell". And it does seem to be limited to living targets. But it is also quick and dirty, and so those are limitations of his tracking spell (if you infer the statement of target to mean that), and references such as the problems that Harry stated in the books, i.e.
Small Favor, Chapter 5: “I tried to collect some of the blood in the
reflective symbols and use it in a tracking spell to follow it back to
its original owner, but it was a bust. Either the blood was already
too dry to use or else the person who had donated it was dead.”
For the first part, Harry is an unreliable witness, and secondly, Harry's particular use of thaumaturgic ritual might have limitations placed on them from his casting style.
So, moving back to RAW. From YS261, the symbolic link has to be freshly taken from the target. But, there are no other limitations inherent in "Solve Improbable or Impossible Problems", YS263.
The most general effect of thaumaturgy allows the wizard to do
something that he wouldn’t normally be able to do. In that sense, a
ritual spell is a simple action on steroids. The wizard tries to
accomplish something basic, but safely ignores any limitations that
might thwart a normal person from trying to accomplish the same thing
by mundane means. Prohibitions of time, distance, and personal effort
mean absolutely nothing to the wizard armed with the appropriate