Just purchased an Alpine head unit - their top model 9855 I believe.
Had it professionally installed in a 2001 Nissan Pathfinder which has a
Bose system. This Alpine has very limited power and is signficantly
less powerful than the factory unit in my wife's Corolla and every
other car I am in. Also the unit does not light when the headlamps are
engaged. It lights up only when I turn the power on to play the unit.
Installer didn't offer any suggestions.

Would the Bose amp be limiting the power of the Alpine. My thought is
to remove the Bose amp and wire the head unit directly to the speakers
to see what I have and then upgrade with another amp. I am new at this
so any help would be appreciated.