Looking for information regarding a whistle I get from the passenger side of my 99.

The sound gets louder the faster I drive.
When I put on any heater position it helps to make the sound "less".
If the the heater position is off and I open the window the whistle gets worse.
I have tried to find the noise by putting tape on the windows and door openings but it changes nothing.
I think the sound is coming from the "Vent" in the dash.

Does anyone know what this might be and if I'm asking for trouble with the air bag under the dash?

 

You haven't had the windshield replaced lately?

Your door could be out of align. But you stated you taped that up?

Is the gap between the door and the front fender OK. The fender should be out a smidge 1/8" or less from the door.

Your concern about working around the air bag module can be eliminated by disconnecting the negative terminals on both batterys. Or, if you're really nervous, disconnect pos + neg cables from the batterys. Wait at least 15 minutes for the capacitors to discharge, then you should be ok working around the module.

 

Excellent way to check for leaks is to tape the outlet vents at the bottom rear of the door frames closed, all windows up, turn the fan on high at any position except recirculate and spray soapy water on the outside of the vehicle. Bubbles will lead to any leaks.

 

Im not sure, but could it be the turbo? On my truck, the turbo whistle sounds like it comes through the passenger side vent. My cousin has a K&N cone filter on his, and it sounds like the turbo is coming through the dash after you . I dont really know of a good way to test this, but just a thought.