Truck - 2002 F350 4x4 Powerstroke, 67k miles, in AZ
Symptom - No hot air when turning mix **** to red (hot side)

I searched the forum and couldn't find anything that pertained to my problem, so I figured I'd post it in case anyone else has the same problem..

Just last week I tried to turn on my heater, and the air came out cold, like the mix **** wasn't doing a damn thing.. After doing a bit of research on how this poorly designed system works, I flipped down the glove box and removed the actuator motor (white thing with 8 pin plug on it).

I then turned on the ignition and with the actuator plugged in, turned the mix **** on the dash back and forth between hot and cold, and watched the actuator rotate.. I figured that it must not be the problem and gave up for the night (short attention span?)

Tonight, I went back to it, and unbolted the heater core cover (directly behind the glove box, seven screws), lifted it up off its mounting, and removed it. I could now see how the flapper door worked..

After looking at the end of the actuator, it looked like I could use a 1/4" drive short extension and put it in place of the actuator to turn the flapper door. To my surprise, the flapper door moved just fine, back and forth (causing dust to blow into my face when it forced the air through the heater core, since I left the blower motor on!, haha).

Confused, I then put the actuator motor back in place, and turned the mix **** again while watching the flapper door.. It didn't move at all.. I removed the actuator from the flapper door, and it turns just fine with the mix ****.. Apparently, this is just a weak piece of junk actuator..

Side note, hardest part of the whole job was getting the actuator off, as you only need to remove one screw, but it is on top of the actuator, near the back of the unit, and then it is held down by three plastic clips that you have to squeeze to pop the actuator off of.. Not a big deal, but I had to feel around the unit to understand it..

Hope this helps the next guy, this forum has been great in the past for me, just wanted to give back to the community.. Now I'm off to search for a good price on this junky part, or else I'll have to reach under the dash and turn my 1 1/2" extension to change between hot and cold air, heh..

 

Great information! Thanks for sharing it!!!

 

I have seen on a Explorer a similar problem. The blend door actuator attachment point to the plastic housing broke. Ford only sell the entire heater/AC box as a unit to effect the repair. Its only about $150.

 

Just to keep the thread updated, I replaced the part today with a new one from Ford, part number 3C3Z-19E616-BA, list price was about $70.68 Working perfectly now..

Now onto the junky brakes..

 

I would like to thank you for posting this!! It helped me tremedously. I had a 200 mile trip to make Saturday morning in low twenty degree temps and my heater would only blow cold air when I drove the truck Friday night. I had left it parked all week with the selector on cold and the door wouldn't close to let it blow warm air. The title of the post also really helped in the search. Again thank you.

 

Ther is a kit out on the market now by DORMAN , for under $20.00 to repair this problem. You still remove the whole heater box, but once it's done, that's it. It works on Explorers and Ranger. May be worth checking out for big truks. It's worth a shot.
There is also a quick fix, by drilling a hole through the actuator stem and inserting a 1/16th " piece of rod in line to run the dorr assembly. That works also.

 

Glad to have helped you out, that is what this site is for! Now, can someone come fix the clunking in the front end of my truck?