how to remove temperature blend door on Ford F-150?
The procedure and pics are as follows:---
you'll probably want to take loose to give max room to get in there to the plentum chamber, including the radio antenna lead on the passenger's side, and the three bulkhead connectors on the driver's side.
Disconnect the three connectors by loosening the 10mm bolts holding them in place, pry the black lockplate off and squeeze the locking tabs to release them from the firewall.
Back inside the vehicle...
The driver's side after removal of the steering column. Disconnect the eleventy connectors going to various things on the steering column, turn the ignition switch to off and wiggle the steering wheel back and forth a little until it locks. This prevents the steering wheel from running off and damaging the clockspring. Now, unbolt the steering shaft pinch bolt (13mm), unbolt the shift indicator (5.5mm) and disconnect it from the shift lever, disconnect the column shifter cable and unbolt the column by removing the 6 - 13mm bolts holding it to the dash support. Also note the three 7mm bolts you'll have to remove to get the dash out as well. There's a 10mm nut on the lower left, and a couple grounds (8mm bolts) to remove in the driver's kickpanel. And while you're down there, go ahead and pull the bulkhead connectors through into the cab that you disconnected from under the hood.
The passenger's side after removal of the airbag. The airbag is retained by one 8mm bolt under the oval shaped cover on top of the dash, and two 8mm bolts accessed through the glovebox. Note, do not unbolt the glovebox hinge to get to those bolts, just unclip it, fold it down, remove the bolts and snap it back into place. The glovebox is spring loaded and can be a pain to get back into place. There's four (or six, CRS, sorry) 7mm bolts you'll have to remove here. There's also a couple more grounds in the passenger's side kickpanel you'll want to remove, as well as connectors to things like the inertia switch, air suspension switch (if equipped), and blower motor amongst other things. This is also where I'd recommend going into the passenger's side front wheel well and disconnecting the antenna lead at the mast and shoving it through the firewall, this'll get you more room to work with when pulling the dash back.
The top of the dash. In an F150 or Expedition, it's got two or three little plugs that you've gotta pop out to get to the bolts.
If everything goes as planned, you'll see something like this. This is the plentum chamber itself, where the evaporator core, heater core, and temperature blend door are. Let's crack that case open and see what's inside...15 - 8mm bolts...
Pictured here are the evaporator and heater cores, and the blend door. The blend door is a snap fit into the case. Pull back on the frame of the door on the passenger's side of it and lift the whole shootin' match out.