Originally Posted by B_Bear

My Nav goes to NIGHT mode when the lights are on and its dark-ish out.

Yours might be "locked" in Day mode. From pg 11-4 of the Nav manual:

"Symptom: The screen does not switch to the night screen even after turning on the head-lights.

Possible cause: The daytime screen was set the last time the headlights were turned on.

Possible solution: Set the screen to the night screen mode using <Day/Night> when you turn on the headlights."