flash2021

all,
this morning (4 degF) driving to work(2008 F150 4x4, extended cab), the cabin heat was barely lukewarm after engine came to temp. I have not had any issues until today, although now that I think about it, one day last week, the temperature dial didn't seem very responsive

*engine heat gauge seems to be working normal, and in usual range
*blower speed dial works in all positions
*no sweet smell or wet spot on passenger floor
*temperature dial now seems to not have any effect (cold/hot= same temp)
*the A/C seems to kick on and off with the button
*the vent position selector seems to work fine (defroster/head/feet/etc)
*coolant level seems to be ok

I did some googling...seems it could be a common problem of the "blend door actuator" failing...anything else I can check? also if this is the problem, any brands (motorcraft YH-1752 is the replacement part I think) I should stay away from or just look for a good deal online?

thanks in advance!

joe mcmillan

The blend doors can stick and or fail. Either way they are a PIA to deal with.
I would first check the heater hoses going to and from the core. If one or both are cold, may it may be a circulation issue from blockage.

TheOldRaker

I had a similar thing a few weeks ago. After checking the coolant hoses that go through the firewall and finding them hot, I narrowed the problem to the Blower door actuator. It's about a 26 dollar part, and little pain in the butt to put in. I definitely got some scratched up hands doing the replacement. Good luck!

flash2021

ok will check the heater hoses after work today. thanks for the tips guys! will keep doing research and such too. i really hope its not the door itself, I don't want to take the whole dash off...I'm not getting a popping noise or movement when going around turns, so I'm guessing its not swinging free

powerranger262

I don't think you have to take the dash off. I have heard of guys cutting a hole through the side of the box, doing the repair, and then jb welding the cutoff piece back in.

flash2021

So i pulled the glovebox down and used a flashlight to watch the actuator shaft as i turned the temp dial. No noise or movement, so thats a sign its seized up right? That or the dial has failed?

DnChris

I had a heck of a time with mine. My blend doors kept clicking and sticking every time I changed the heat. It's not that big a deal as long as you have a mechanic that knows what they are doing. I had mine done for under 100 bucks. It's about an hour labor and parts, but don't do it yourself. It's really not worth it.

flash2021

Just an update. Replaced the blend door actuator and it seemed to work. The original one was not moving. Once i put the new one in, it repositoned as i turned the dial. We'll see on the drive to work tomorrow!

HeathMc

So was it a tough job?

flash2021

so it took me about 2 hrs. this was the first repair I've done on the truck (my acura on the other hand, i've torn into the dash,pillars,etc a bunch) and followed some videos on youtube. the 3rd bolt in the back is a PITA but i used some elbow grease and eventually wiggled it out.
put the new one in and THEN hooked up the battery (or else you'll mess up its homing function) and it seems to work now. i wonder what caused it in the first place

i didnt take it apart bc time was short, but I'll open up the old one tonight, maybe stripped gear or something.

7/8MM socket, screwdrivers, plierss, plenty of light and some patience helps