i'm hoping someone can shed some light here. i've just bought a brand new scion (T1814) unit and had it installed. everything works fine so far, it powers up, plays music, etc. but when i turn on the headlights, the entire deck goes black. no light what so ever, but it's still operational as far as the sound goes. music still comes out, but i can't see any display or lights. any insight would be greatly appreciated. thanks in advanced.

 

There's a dimmer switch left of the steering wheel, right above the change shelf - turn it all the way up.