So this has happened before in the summer, but rarely. Now that it's pretty cold how. It'll happen when I start up the truck cold (not all the time) It'll last for about.. 10 seconds or so.
But it'll go on for like 30 seconds when I'm driving 30-60 mph. It can't be anything like wheel related. Because it'll happen when I'm stationary.
It doesn't matter if the a/c is on or off, it'll still make that sound. But from where I am sitting it sounds like it's coming from the passanger side.

I wanna say the belt, but if it were that then it'd be more squeaky. I tried to pop the hood and listen, but that didn't do any good. So, if anybody can watch this video and see if it sounds familar or have any ideas. That'd be great. I'm gonna look more into it this weekend though.

http://www.youtube.com/watch?v=3kJhc...ature=youtu.be

 

If it is coming from the right side, may be from the heater damper. Try moving the hot/cold ****, or the maybe the fresh air damper while the sound is on. If it changes maybe is stuck or a vaccum leak.