Power is supplied at all times

WARNING: This page is about a different car, the 2004 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.

through 20A fuse (No. 31, located in fuse and fusible link box)
to audio unit terminal 6
through 10A fuse [No. 3, located in fuse block (J/B)]
to display unit terminal 1 and
to AV switch terminal 1.