If both heater hoses are hot (not warm) and your sure the blend door is operating properly then you should be getting hot air out unless theres insufficient coolant flow through the core or the coolants not coming up to temp.
1. The heater hoses should get hot before the upper Rad hose. Start your truck up cold with the heater temp set to hot, fan on low speed and let it idle. Keep checking the heater hoses as its warming up. They should start warming up fairly quickly. If your truck has a hot water shut off valve inline with one of the hoses make sure to check before and after the valve and that the temp your feeling is consistent along the entire length of both hoses. Note, they should get hot enough that you cant hold on to them in short order. If the inlet hose is getting warmer before the return hose, then there maybe an obstruction reducing coolant flow (plugged core or hotwater valve). If the upper rad hose is warming up at the same rate as the heater hoses, then suspect a stuck open thermostat.
2. If your truck has A/C is the compressor on? If so pull the compressor plug and see if it starts getting warmer.
3. Double check the blend door. If its cable operated I would unhook the cable at the door actuator and manually manipulate it making sure you feel/hear it hitting the box from side to side. Note, you may be able to remove the lower vent outlets and look up inside and actually see the door.
4. Do all outlet positions work, i.e., defrost, dash vents, floor vents, etc. and do all fan speeds work with normal air flow out of vents for the speeds selected?
2001 Ranger Edge 3.0 V6, 5 speed M/T
Limited Slip Differential, James Duff Traction Bars
Kumho 30x9.50 15 MT / Black 297 Series 15x7 Rims