Nissan switches across the fleet can be a little dodgy.
I suspect the contact inside the s/roof operating switch is stuck in the open position.
Two options, direct your hairdryer onto the switc, not too much heat never too hot to touch! Or to do any damage to the switch or surrounding panel as you only want to warm up the old internal grease. If no joy remove the switch and after warming it up a little for half a hour or so you'll be able to dismantle the switch to free up the small contact internally.
Wednesday, January 20th, 2010 AT 5:33 AM