My 2005 f150 had some noise coming from vents like something was rumbling inside when It was on lvl 3-4 when a/c or heat was on... Now recently the air just stopped working all together.. so both the a/c and heat have no air flow when turned on.. any suggestions?

 

Pull the blower fan out and look for broken fins on the squirrel cage, that'll cause the rumbling as well as if any debris is in there. Check the fuse for the blower fan, if it's good check to see if your getting 12v at the blower when the system is turned on fan set to high.

If you can't find anything there, take it to someone who knows how to work on automotive hvac.
.