Heater Stuck on Hottest Setting Due to Broken Heater Blend Door on Ford Explorer

Problem Description and Possible Solution

A failed heater blend door or actuator can cause the temperature control for the HVAC system to stop working. A clicking sound from the dash area would commonly indicate an actuator fault. If the heater gets stuck on the hottest setting, the heater blend door may be broken requiring replacement of the heater box to repair the issue.

Problem Data
RepairPal Verified
Average mileage: 110,694 (30,000–300,000)
19 model years affected: 1991, 1994, 1995, 1996, more1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012
361 people reported this problem
Viewing 1 - 20 of 170 comments
When switched to hot it would sound like a timex watch. One day it stopped and would only blow cold. i called Ford and some local repair shops and no one could give me an answer wanted to put it on their machine to charge me $95.00 so i called Autozone the man there told me I needed a repair kit for the blend door $16.00. Now the problem is there was no instructions on how to get to this box. I did find out that the whole dash has to come out. I need some instructions from that point.
Blend Door Actuator AKA "Click of Death"

It began simple enough with a clicking sound coming from the A/C. First the actuator controlling the vent settings quit, leaving defrost as the only setting that worked. Then the clicking got louder and then the heater quit in December. After much searching on the internet, we found a way to set the actuator on hot. This problem seems amazingly common and has been for years. Why hasn't Ford fixed this?
Heater control ticks and wont change on demand. IT acts as if a vacuum line is loose or broken. If you turn the fan on wide open and keep moving the control to change from floor to vents. Eventually it will slamm and change. I'M NOT SURE HOW TO FIX. CAN YOU HELP?
My 2005 Explorer has had a thumping noise in the dashboard for over a year whenever I turned the temperature knob either up or down. Now, my heater seems to be stuck on extremely hot, even when the air conditioner is turned on. This is problem is even more difficult to live with since none of my windows will go down. I am also experiencing a thumping noise in the rear driver's side of my Explorer.
I had this problem and I replaced the blend door actuator now it seems to work fine. But i have a rear/backseat blower which blows heat/ac to the backseat and when I turn it up, I hear a clicking sound similar to what I heard before I replaced the actuator in the glove compartment except neither hot nor cold air comes out when I change the temperature on the automatic climate control. except this noise is coming from down low in the middle of the dashboard counsel. Is there another actuator that I have to replace?
blend door broke twice ,now i have to manually move summer or winter also seemlike the fan isint blowing as hard
My blend door is broken. I can turn the knobs to go from warm to cool, but it doesn't make a difference. I have to have the ac set to Max AC to get cool air.
Heat blend door stopped working. Bought a new actuator at the dealership. Installed myself by splitting the panel on the driver's side bottom and removing a zillion screws, then popping the panel loose. R&R'ed the actuator and put it all back together. The normal method is to remove the entire dashboard and metal framing. This method invented by me took about 2 hours.
There is a solution to the blend door problem!! it's a steel kit that goes in through the glove box and does not require dash removal. Kit costs 119$ and takes an hour. check it out
my heater vent is stuck open or on! i live in 110 dgree weather in the summer no bueno! constant clicking... i took out the ac fuse under the hood in the black box check manual. and then i plugged driver side vent with toel because i wear thongs and was getting burnt toes! anyone know how to fix without taking whole dash out? my mechanic says to bypass the heater hose with an elbow and let it blow in the engine? idk im a girl and no some about cars but not a whole lot... and cant afford to fix at shop. but im glad to see im not alone!
REPLACED THE BLEND DOOR ACTUATOR. Was definitely broken little pinion gear. Blows HOT air on Hot setting (variable setting knob set to full red) and slightly warmer than outside air on COOL setting. Have confirmed that acuator is working.
Change temperature knob to cold and hot. Just gives me hot heat all the time. A/C will knock heat down, but this is not good for really hot days. Replaced heater control valve on passenger side of engine. Follow heater hoses from heater core, have a helper move inside temerature control knob to cold and then to hot, and check to see if your heater control valve is working. It works with a vacuum, and your vacuum line may just be cut/broken/disconnected. Otherwise if valve does not move, replace. It is a 18 dollar fix.
Blend door sticks so heat is all 'on' or all 'off'. Put new controller in and checked signal - it varied properly. Shop said the 'door' is a plastic that deforms after time and sticks in extreme positions. If you could access it with a wire you could probably knock it loose so it moves.

Only solution that works so far is to turn control knob from one extreme to the other. If lucky it breals loose and goes back to normal for a while.