Could be... could be several other things. Your best bet is to pay some technician to at least tell you what is wrong. Then there are lots of folks here who can help recommend a repair. It is very unlikely someone can diag your problem from hundreds or thousands of miles away accurately. You dont want to spend money to fix what isnt broke. Its cheaper to know up front from a trained technician.

It could be anything from low coolant, to stopped up heater core, to broken actuator or broken blend door. It should not affect BOTH front and rear heaters at the same time so you should get heat from one of them. If you dont get heat from either I would look at coolant level first. The outside temp indicator will not affect the heater operation.

 

Thanks Homer. I'll take your advice, but it's definitely not the coolant (radiator coolant), that was the first thing I checked. And yes, no hot air in the rear nor the front.

 

Gerdva, the rear system is not dependent on the front system control. They have separate temperature control. So unless you have TWO blend door actuators or blend doors broken it has to be a coolant level issue. If both systems are broke then I would get a professional to look at it first to see what your exact problem is or you will just be throwing parts at it.

Edit... I am also assuming your engine coolant is getting to normal operating temperature.

 

I have 97 F150 5.4 vents only blow hot air... When i turn temp. control **** from hot to cold i hear a click sound under dash.sounds like something is operating . I need help!!!

 

I have been reading the posts and cannot find my symptoms, or i just missed them.

i have a 98 Expy, EB, 4.6l, 2wd. I have lost heat in the front. It first started by changing from blowing from the vents to the defroster when i would give it gas or if it had to down shift to get up a hill. Now the problem is that there is very little heat coming out at the feet, very very little coming out the vents no matter if it is set at panel, panel/floor, defrost/floor, with heat maxed out, you can hear it pushing alot of air that seems to go nowhere or out the defrost vent. The heat works great out the back. When i put it on max AC i can hear the door change and get max air flow out the vents.

Does anyone have any suggestion or can point me in the right direction as the wife and kids are darn cold in 30 deg weather with cold air blowing on their heads.

 

I was able to see that my blend door is working properly, without having to take it apart. It is a small white box, located under the dashboard, near the floor, in the center of the vehicle, closer to the passenger side. I used a flashlight to locate the blend door. Then, with the heater on, I turned the control to cold, and watched the blend door move (spin) 90 degrees. Therefore, my heater problem must be something else.

 

I havent ever been able to see the blend door itself move outside the plenum. I have been able to see the white post of the actuator turn, which only tells you that the actuator itself is working. Do you hear a distinct change in airflow sound when it opens and closes? If you do then it is likely OK. If you dont you likely have a broken door. Otherwise you could have low coolant or a clogged heater core.

Another clue to broken door is if you see large black plastic piece turning with the actuator post. That part is usually tucked well inside that you cant see it in operation. Meaning the door shaft broke and slid down the actuator shaft.

 

Thank you. You saved my life. I added water to the radiator, and the heater suddenly works after 1 year of being cold. You are the greatest.

 

Great, just better find out where the water leak is before it gets worse.

 

Hi.

Sounds like you didn't take anything apart to see the door. Is this right? I used a flashlight to look under the dash where the center console connects to the dash from the passenger foot well and couldn't be sure what I saw. I did see something white in color but not clearly enough to discern movement.

So is the door black and the actuator white? I'm going to take another look--thanks for any advice/clarification

dbro8863

 

Actually, I took the blend door actuator completely out, by using a great amount of force. I took apart the actuator, and verified that all of the parts were in excellent working condition. Then I forced the actuator back in place.

After all of this, I realized that I can actually see it moving, if I watch it closely. It moved just fine, but my heater still did not work.

Then someone emailed me from this blog here, and told me to add water to my radiator. Low and behold, the heater started working after about 1.5 years. I guess that I drove around for 1.5 years without enough water in the radiator.

I hope this helps. Yes, the actuator in my 98 Expedition is white, and it is located under the dashboard, along the floor, about 2 inches to the right of the center line of the vehicle. Of course you will have to remove the center console to get to it. I removed my center console about 5 years ago, so that my kids could easily get from the front to the back, and vis-a-versa.

 

OK so I've read all the posting about the AC/Heat issues but it seems to me that they are mostly about heat...here's my problem...please help me if you can...

Just today I turned on the MAX AC in my truck and it started blasting me with heat. I tried everything I could think of then called my hubby to ask if I was doing something wrong. He checked it out when I got home and found that the AC works fine in the back of the truck it is only the front that is blowing heat. It was a fairly warm day around 70ish but the thermometer in the truck said the outside temp was 60. Then after the sun went down and it started getting cooler the thermometer rose to 61. Hubby followed some of the directions on this site and discovered that we can't get to the plenum by removing the glove box. He will have to remove alot more of the dash, but he is concerned about accidently deploying the passenger airbag. He is a pretty good mechanic but old school and is kind of scared about working on this newer vehicle. He says that he can hear the door opening and closing when he moves the control from defrost to heat or to AC. Honestly I can't afford to take it to a shop or the dealer. It seems like ever since it hit 120K miles, everything is breaking. We gotten some great info about diagnosing MAF/Vacuum Leak problems and it saved me a lot of money. PLEASE HELP US!!! Any and all info/advise is GREATLY appreciated. Thanks...Suzyqu65 suzyqu1@verizon.net

 

Just make sure to disconnect the battery and allow a couple minutes for the modules to lose power. Ive handled about 1000 airbags still hot and active and never blew one. You would almost have to try to blow one. In fact in all these years Ive never seen one blown by a tech working on one. So dont wear yourself out with fear.

Its a big job to remove the instrument panel but as long as he has tools and some experience this job is very all systems go. You can even get just the blend door itself at the dealer and it can be replaced without removing the plenum. Once you get the console and dash removed, then take out the dozen or so screws retaining the top cover panel on the plenum and you can remove the door assembly and replace it in a few minutes.

I recommend setting the temp control to middle position BEFORE you start tearing down so the actuator is not binding the new door on installation. Once you have the door replaced, reinstall the dash and console and enjoy the fruits of your work. Good Luck.

 

Hey guys, just wanted to say thanks for the info posted. If you could please send photo's too jessiep916@live.com I would appreciate it very much.

 

On my 2000 Expy I got frustrated trying to find the last screw holding the floor vent distribution duct in. The click-able thumb below shows the location of the 2 screws. The forward one is really fun! Getting this screw in and out was the worst part of the entire job for me.
Big suggestion; if you have an Expy and want to see if the blend door works, cut the hole in the plenum. You can do this in very quickly as compaired to removing the center console and pulling the vent duct and blend motor off.