whistling noise when heat is cranked

Hello,

Recently I've been driving around and been noticing that when I crank the heat, a loud whistling noise sounds like it's coming just in front of the dash. It gets less annoying as you turn it down but is still there. Also I've noticed that the heat gauge on the dash itself has been a little bit lower then usual. It still goes up, but just comes about a third above the C then rather making it the usual half way point.

It's a Toyota Tacoma 2009 TRD with approximately 103000KM on it. Sorry for poor explanation, my tech skills as a mechanic are poor at best.

 

pull out your cabin filter and have a look in there for a leaf or something else first

 

blower motor

 

I had this exact same thing awhile back. Try pulling out the cabin air filter and replacing it or cleaning if it is not so bad. Then under the filter, pull out the squirrel cage type fan itself. Mine had a few acorn shells jammed in it by a chipmunk or something. The shells were causing the whistle. It was an easy fix and hasn't whistled since.

I also learned that you should always put your fan on recirculate before you park the truck. It keeps the critters out.