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Hello, I'm new to this forum so bear with me. I have a 2007 Pilot EX 6 Cylinder with an air conditioning problem. I have what seems like heated air blowing from the front vents and cold air from the rear vents. No matter what temperature setting I place the front dial control on, It blows hot air. The only releif from heat is when I turn the unit completely off. I purchased the vehicle a year ago with a little over 100,000 miles on it, so I don't know what service (if any) has been performed on the car. The air seemed to be working fine until a week ago. When I turned the heat on for a while and then tried to go back to cold air, it would only blow hot air. I turned it off. Got in the next day and the cool worked fine until I turned the heat back on. Since then it has only blown hot air. However, the rear unit blows ice cold air just fine. I've tried to readjust all the controls to no avail. Any help would and will be greatly appreciated.
 

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Rear vents as in center console between the front seats? These are completely separate heaters and evaporators. First check the heater valve located on the firewall right behind the engine - what is it set to and how does the lever rotate the valve? Have someone play with the knob while you are looking at the valve. Chances are that the lever screw is loose and while your lever is moving freely, the valve does not turn and is stuck on hot. Tighten the screw, use blue locktite.
 
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Rear vents as in center console between the front seats? These are completely separate heaters and evaporators. First check the heater valve located on the firewall right behind the engine - what is it set to and how does the lever rotate the valve? Have someone play with the knob while you are looking at the valve. Chances are that the lever screw is loose and while your lever is moving freely, the valve does not turn and is stuck on hot. Tighten the screw, use blue locktite.
Yes, definitely try that first. Here are some visuals to help you locate it:

http://www.piloteers.org/forums/69-2003-2008-pilot/118274-help-front-heat-doesn-t-work-but-center-console-rear-works-perfectly-fine.html#post1219817
 

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Discussion Starter #4
Addtional Info

One more thing I forgot to mention: Before the above happened, when i would place the temperature control dial around to the middle setting (halfway between the hot and cold settings) i could hear a kind of clicking/scratching noise -- i no longer hear that noise. The noise was very annoying. Not deafening but noticeable.

Questions: Should I change the cabin filter, charge the cooling system, and maybe check the blend door actuators? The Cabin filter and Charging the system seem like something I can do myself. But how do I check to see if the blend door actuators are working -- and does my Pilot have one or 2 of those blend door actuators? One for the rear and one for the front?
 

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Discussion Starter #5
Thank you "can" and "plplpl"I will give that a try and let y'all know if that was it.

And yep, the rear vents I mentioned are the one in the console,

Appreciate the help!

"plplpl", thanks for the pics ! Invaluable help!
 

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Since you heard the clicking / scratching I think you should check out the front blend door. The Pilot does have separate blend doors for the front and rear. I believe if you adjust the heater controls you should be able to see the door or the arm connected to the motor moving. You’ll need to look under the dash to find the location but I believe it’s on the passenger side since that is where the front ac core is located.
 
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Discussion Starter #7
I think I found the heater valve (i think)

Thanks for the help. I think I found the heater valve (see pic). I cranked the car, tuned on air conditioner/ heater and I had someone work the air conditioner/ heater controls (knobs, dials, buttons). The lever/linkage thingy never moved -- in fact, it did nothing at all that I could detect. Prior to that, I checked that screw/bolt you mentioned -- it was tight and would not budge. (I'm going to try to upload a pic.) Also, after cursing the Honda engineers for making the cabin air filter so hard to access, I finally managed to access the cabin filter and man was it dirty! The compartment had some small leaves and dirt and grime in it so I vacuumed that out too. So, where do I go from here? Do I replace the heater valve? Is that something I can do. I've changed break pads, replaced alternators, etc. nothing major. Can a novice like myself tackle this? Thanks for all the Help!
 

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If it never moved then I'm going to say something else is wrong. Also I'd think about this, since there is only one heater control valve why would it be an issue if you are getting hot one "end" and cold on another ?

I'd start with checking for HVAC codes
. You get these from the HVAC controls - not sure which unit you have or I'd post the "how to" on getting them.

Sounds more like an air mix motor is not working.....you did state "i could hear a kind of clicking/scratching noise -- i no longer hear that noise"
 
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Rear vents have their own temp control.
If the front is never moving, and you absolutely need heat, you could unscrew and turn by hand, then investigate. Seized wire in the cable, or wire disconnected from the knob would be obvious suspects. Yours seems to be seized fully extended out of the valve end, so disconnect sounds more plausible to me.
 
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Halleluia! the Air works again, but...

Okay, so I tried to move the heater control valve (actuator arm) manually with the cable still attached to no avail. I then used a broken golf club (I'm sure that's a standard tool for automobile repair, right?) to pry the cable hook off the actuator arm and once removed I was able to move the arm in the opposite direction (I assume that is the closed position), my air conditioner now seems to work. Halleluia! I have not given it a full test because it was cold yesterday in north Georgia. Anyhow, it ain't blowing hot air no more (that's how we say it down hear in the south). In the next day or two, it'll be hot and I'll give her a real test. So now my question(s) is this: What's bad, the heater control valve, the cable, or the controls that cause the cable to actuate the heater control valve arm? Since I was able to manually actuate the heater control valve, I'm guessing that its the cable or the controls. So, how do I check (test) those items?
I'd like to thank each and everyone who has contributed to this thread and helped me with this problem, your help has been invaluable -- Thank you all so much -- especially "can" & "plplplpl"!:grin:
 

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Did you check for HVAC codes yet? Is so were there any.

So what moves the cable on the other end.....humm. Could it be the air mix motor


Yes, there is some "linkage" involved.

You need to go to the "other" end of the cable - you can disconnect it and then manually move the cable to see if it is "stuck". Inspect the linkage to be sure there isn't a clip or rod that has come off. You could then turn the key to "on" and move the temp from full hot to cold and see if the "arm" the other end of the cable attaches to is moving.

If not then test the air mix motor.
 
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JSTEED...did you resolve your heating issue? I'm having the exact same problem. I've checked the Motor Assembly, Air Mix, and once the cable is removed, it moves freely. In fact, this is how i turned down the heater. The cable will not move. I don't think the cable is seized, as it has no movement, what so ever. I don't believe a teflon coated tube could seize in this manner. I don't know what the other end of the cable connects to. I'm fairly certain that is where my trouble is. Any idea's where it connects?
 

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The "other end" of the cable is attached to a lever that is "moved" by the air mix motor. In this pic you can just see the cable going to the lever, the rod off the air mix motor connects to that lever as well.
 

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My wife mentioned that she had been hearing "clicking" when she used heat or air. The picture you attached (thank you) also kind of looks like the end of the cable in the engine compartment. Just to confirm, the diagram you attached is in the cabin? If so, it sounds like our air mix motor might be out. is this a difficult repair?
 

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I know this is an old thread. I just bought a used 11 Pilot. I fixed a similar issue on mine.

Symptoms:
1. rear a/c ice cold for a while then no air at all from the rear (the evaporator kept freezing until forming ice preventing air flow).
2. Front RARELY worked like it should. When it did, the passenger side was usually noticeably colder than the driver side. Air flow normal, just warm. It usually started cold (still taking about the front) then warm after about 20 minutes or so.
3. A/C manifold gauge readings:
At start up through first 20 minutes(ish).. Low 25 High 170
After 20 minutes(ish)... Low slowly dropping from 25 until reaching nearly 0. High strayed around 170.

Diagnostics:
1. Recovered refrigerant (most call it freon), used a vacuum pump to check for leaks. No leaks. Then filled to spec. No change :(

2. Recovered refrigerant, replaced the a/c pressure sensor attached to the High side line. Refilled refrigerant. No change :(

3. Did more research. Lead me to change the front expansion valve (attached to the evaporator under the dash). Recovered refrigerant, replaced expansion valve, refilled. Problem FIXED!

Good luck to you all!
 

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Hello, I'm new to this forum so bear with me. I have a 2007 Pilot EX 6 Cylinder with an air conditioning problem. I have what seems like heated air blowing from the front vents and cold air from the rear vents. No matter what temperature setting I place the front dial control on, It blows hot air. The only releif from heat is when I turn the unit completely off. I purchased the vehicle a year ago with a little over 100,000 miles on it, so I don't know what service (if any) has been performed on the car. The air seemed to be working fine until a week ago. When I turned the heat on for a while and then tried to go back to cold air, it would only blow hot air. I turned it off. Got in the next day and the cool worked fine until I turned the heat back on. Since then it has only blown hot air. However, the rear unit blows ice cold air just fine. I've tried to readjust all the controls to no avail. Any help would and will be greatly appreciated.
Did you get this fixed? Mine is doing the same thing.
 

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Hi Amy, welcome to the board!

Just to be sure, are the rear vents blowing cold air like what the original poster mentioned?

Do you hear a clicking noise coming from somewhere behind the dash?

Is it the front A/C that’s giving you grief?

Are there any other symptoms?

What year is your Pilot?

Sorry about the 3rd degree with all the questions, just want to make sure you get pointed in the right direction.

Dan
 
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