Here is my problem, I hope someone can help me out on this. On the first hot day this year I finally turned my heater control from hot to cold to run the AC, but it still came out hot? I said what the @#%@! I didn't know what was up so in a desperate plea for some cold air I had my buddy kick his feet under the dash. Presto Cold Air!!!! Now that it is getting colder I went to put my heat control to hot, and no hot air? Tried the old kick again but it is not working. Could something be stuck somewhere preventing my hot / cold air flapper (if thats what you would call it) from flapping? I really don't want to have the dealer charge me mega bucks for something small.

 

Any chance it is just the **** not turning the shaft on the temp control? These crack pretty easily.

 

I am pretty sure its not the ****. It has never been off, and it still stops when it is turned all the way hot or cold, but I am going to check it right now just to be sure. I noticed that the heat selector switch is electronic, is there any way to diagnose the switch itself with a multimeter?

 

Update.... I just went out to diagnose my problem. Switch looks good. I started to take apart the under dash on the passengers side and I gave it a hit with my hand, and presto! Heat! I think that the flapper / blender or whatever its called is getting stuck. Maybe it needs some lube. Anybody know where the flapper is so I can take it apart and lube it up?

 

My '99 F150 gave me a nice, ice cold surprise as the weather turned this week to COLD>>>>>
I would turn my temp control **** and it SEEMED to be working as it stopped on the red side and stopped on the blue side when I turned it either way. It looked normal, and hey, it sure worked for AC settings this summer...
Well, after freezing all week I figured I would yank the **** to start at the cheapest place to fix first and Viola' the white plastic shaft the **** sits on is stripped almost round and not demilune as it should be. (half barrelled)
Some teflon tape fixed this issue after I marked shaft with marking pen to see where I started before turning it , turned it with the needle nose pliers to the "hot" side and replaced **** accordingly.
You may check this first, it is worth fighting the **** to get it off the shaft and fix this for next to nothing.
~ Victoria

 

Hi Idezyne4u and welcome to FTE

It's nice when a simple fix works. Now if only they were all that easy.
How cold is it where you are?

 

well today it is about 55 dgress ( for Ca. it is cold) considering we were 90 dgrees Monday and now we can expect snow tonite

 

brrrrrr
lol
It is sitting at about 25 here right now with not a cloud in the sky

 

I am having similar problems with my 99 F150 and the heater control. I've read a lot of posts about blend doors and actuators but I'm not sure that is the problem. Thought I would post for some more advice. I checked and double checked the **** and I am pretty sure there is no problem with it.

I know the door is supposed to be electronically controlled, but it sure seems to be somewhat dependent on vacuum. When I start the truck in the mornings, even after the temp gauge shows the truck is plenty warm, it will only blow cold air. If you get on it pretty hard leaving a stop light you can feel the air coming out of the vent getting a little warmer and when stopping at the next light the air gets cooler. It never gets as cool as it was before the last stoplight and so eventually the air gets really warm and doesn't cool down at an idle. Of course by this time I am just about to work.

Also, once the air does get really warm, the control switch doesn't seem to have any effect on the temperature. You can move it to a cooler setting but the air stays warm, even on AC. Seems like bumps and potholes also effect the air temp sometimes.

I think the actuator is working because I can hear the motor when switching the control from cool to warm or warm to cool. Is the actuator locatred behind the glove box on F150's like is posted in the blend door fix? The actuator motor noise seems to coming from somewhere in the middle of the dash, just above the hump in the floorboard.

One more thing, when the AC is on and blowing cold air, if you hit the gas pretty hard (like dropping down into passing gear) you can hear a clunk in the dash and suddenly the air from the AC gets hot.

Any suggestions, advice or comments will be appreciated!

Thanks in advance,
Kevin

 

Hi Kevin and welcome to the forum

The actuator motor is located just above the hump in the floor. You get at it by removing the black plastic trim piece in between the floor and the dash. it just has a couple screws or pins that hold it on. I think I'd remove the actuator and take a look to make sure the blend door isnt broken or binding. Did you find the Explorer blend door fix in the Explorer forum?
As for the A/C problem I'm really not sure. The vacuum motors could be affected by the drop in vacuum when you accelerate hard if there is a leak in the system. However, the vacuum operated doors only control the air distribution and not the temperature.
I'll try to get some more info for you here.

 

Just make sure you are not working on two separate issues.
Almost sounds logically that something is "loose" when it comes to temp changes <<" if you hit the gas pretty hard (like dropping down into passing gear) you can hear a clunk in the dash and suddenly the air from the AC gets hot.">> sounds like something is not attached someplace.


As for the temp **** issue? make sure to mark the **** first with a pen and turn it with needle nose pliers as it will not turn with your fingers only.
I tried this without pliers and thought I was turning it when in fact I was doing nothing.

 

I also have 1999 f-150 and my heater this winter also decided to stop working. The fan works fine and also the A/C but I'm just not getting any heat at all. My friend said that it was some sensor in the glove box that needed changed and that it would only be a 5 minute job but I looked in to it and took off a portion of my dash and couldn't find anything. I recently read some other similar problems posted and it sounds like it may be the **** not allow the heat door to open but I really don't know. Does any one have any ideas of what my problem may be some help would be greatly appreciated.

 

I have now learned the term, "demilune" for that common "half-barrel" shaft shape, and that it is a common furniture descriptor.

(e-genuflects towards Idezyne4u)

My life is complete and I can die happy.

 

ok checked the blender acutator, it turned but it was slow and not really sure how far it is supposed to turn. the switch appears fine. the other switch the one to select floor and defrost and things works fine if you turn it it will change. blower works great but still no heat. heater core was new last year so i imagine it can't be a bad heater core. what else can i check i removed every visable vaccum line and can't find any cracks or leaks anywhere. i'm at a lost and the ford dealership is no help any ideas?

 

I am having the same problems with my door not flapping open or closed. I think it has to do with a vacume. If I hit the brakes real hard I can get it to flap over and start pouring out heat. I guess i will have to tear into it and find out what it is beacause it was 9 degrees here today.