Among the documents at the link in my post #6 is this one
. It specifically addresses the issue of the brake signal working "backwards" on some 2006 coaches. This mis-wiring is also the subject of the service bulletin
to which I linked in the earlier post.
If you make the change indicated you should not need to add a relay to your pre-wired coach to "reverse" the brake activation signal.
I can send you links to a source for the connector shell and pins needed to connect to the factory-supplied connector
. You just need a suitable crimp tool. This will keep you from cutting into the wiring to connect your controller pigtail
. Just let me know.