Can I trouble shoot a heater problem on my 2001 Ford F1505.4 V8 engine ?

I had the same thing happen on my 2000 f 150 so get in your truck close your door turn your key on but dont start it ok now, your heater control knob is the one in the middle turn it from cold to hot and you should hear a little motor but if you dont your acuater is bad and the door is not opening so right in the middle of your truck on the floor there is a black box type thing bopen it up and you will see the acuater motor re[place it or sometimes you can mess with them and get them working again but you cant miss it its on the floor right in the middle of cab!!