^okay that is certainly interesting. I have sport package so air ride in the rear. It looks like the e46 and e53 final stage resistors are the same and my e46 definitely needs one. The fan is all over the place and sometimes will just randomly shut off for a while. So I'm gonna order that for my 3 series and than I can try and plug it in to the x5 as well to see if it takes care of anything.

I guess my question here is is anyone familiar with that sound coming from the hvac unit? It certainly doesn't seem right.