I have a 1997 Ford E-150 with no heat so i am trying to open the blend door for winter to let the heat in. how do i do this?

There is no process, just make sure the battery negative cable is disconnected before install the part.

Air Temperature Control Blend Door Failure No Heat or no AC (dependes on where door sticks)

In all modern cars there is a tiny DC electric motor driven gear drive that moves a plastic door that blends heated and cooled air from the AC and the heater core, this is called (interestedly enough) the air temperature control blend door actuator. The motor that moves this door fails because the door starts sticking from warping, most common complaint is no heat but it can be no AC as well. To replace these parts (blend door and blend door actuator) you must remove the entire dash from the car. Always have this problem confirmed by a dealer or qualified repair shop as it is a very expensive repair.

Other causes of no heat in the cabin are engine thermostats that are stuck open (engine runs cold) or air bubbles in the cooling system.

Air Temperature Control Blend Door Failure No Heat or no AC (dependes on where door sticks) This is well documented problem on this make and model.

In all modern cars there is a tiny DC electric motor driven gear drive that moves a plastic door that blends heated and cooled air from the AC and the heater core, this is called (interestedly enough) the air temperature control blend door actuator. The motor that moves this door fails because the door starts sticking from warping, most common complaint is no heat but it can be no AC as well. To replace these parts (blend door and blend door actuator) you must remove the entire dash from the car. Always have this problem confirmed by a dealer or qualified repair shop as it is a very expensive repair.

Other causes of no heat in the cabin are engine thermostats that are stuck open (engine runs cold) or air bubbles in the cooling system.

Looks like it sits on top of the heater housing left of the blower. You may be able to see it by removing the glove box. These things tend to strip their plastic gears. If you heard a lot of clicking before it failed, that is what happened.

there is a ton of info on google for this here is some pictures for a 97 explorer. should be the same as your truck. it is the same as my 2001 F250. my blend door was fine and had another problem. if you remove the glove compartment then remove the black case to the heater core, you can easily see the door to your left. the actuator is on top of all this. as i said, google Blend door repair video and you will have all the info you need.
http://www.blenddoorfix.netfirms.com/

this may or may not help Tim:

http://www.allpar.com/fix/heat.html

Check and adjust or replace the blend door cable also make sure blend door moves fairly easy

Under the middle of the dash is a part called a blend door actuator it is located between the floor board and the heater housing. It control the door that opens and closes allowing heat to exchange.These go out all the time.

Search for a blend door problem, I have the same issue. It is fixable but a pain.