I did a quick search and found a guy that has a 2008 Pacifica. He had "to pull out the bottom drawers of the dresser, reach under all the flexible duct work, under the hot water line from the water heater and there they are."
You can find the post/thread HERE
He also suggested in another thread (HERE
) to a guy with a Dolphin:
Another way to locate the approx. location would be to open the basement compartment section where your basement a/c is located. You should see a round vent going towards the rear of the coach and a rectangle shaped foil return duct coming in from just above the a/c unit. Then go to the part of the coach just above this return vent and start looking. National RV was pretty creative when hiding the location.
If you still can't find it or if nobody else chimes in here, you can always ask the question over in the National Owners Forum here at iRV2 as somebody has got to have the answer there ...click here