If you put it on battery back up you blew a fuse
This is a known problem with battery back up to the car while changing a battery or
you didn't plug everything in on top of the battery distribution block
back in the same place.
That row or slots for the cables on top has slots that are not populated
with connecting pins hence if you plug into those you won't get a connection.
This was discovered on the stereo board.
there are 4 hot lines that go from the top of that battery distribution block forward I believe check those for power see the above link.