I'm sorry to bother y'all with this question, but in searching past
postings, I found some that were close, but not quite what I need to
know.

I recently installed a new Brinks security light (model 7010) and
added another halogen-light fixture via junction boxes and 20 feet of
conduit. I connected the second unit to the first using wire-nuts on:
white:white, black:black and green:green. The second light works when
turned on manually (via toggle light switch) but the Brinks unit does
not and the motion sensor does not seem to work.

What have I done wrong?

Any advice you can provide would be most appreciated.
Lee