durango, front ac hot, rear ac vent cold... suggestions?

Our 2000 durango is blowing hot air from the front vents and cold air from the rear overhead ac vents when the truck's air conditioning system is turned on. The compressor clutch engages. the metal tubes/lines under the
hood are both 'hot' to the touch. what could be the problem? plugged lines into the front condensor? non functioning or stuck vent actuator door or motor? any suggestions would be appreciated!
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On Wed, 28 May 2008 12:04:32 -0500, jo wrote:

just a stab but check the blend door and make sure its functioning.
--
Chris

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On Wed, 28 May 2008 12:04:32 -0500, "jo"

Q: do the rear overhead vents also provide heat when the heater is on (by design)? If not, I'd suspect either the blend door, or the heater valve.
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On Wed, 28 May 2008 15:48:02 -0400, PeterD wrote:

the over head a/c unit is a/c only, heater vents are piped through the center console between the front seats and runs off the heater core in the front of the truck.
--
Chris

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On Wed, 28 May 2008 20:03:49 +0000, "Christopher D. Thompson"

Blend door or heater valve (or both?) are my guess then.
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On Wed, 28 May 2008 18:59:00 -0400, PeterD wrote:

there is no heater valve on a durango. I looked at my 99 durango just to verify that, and as i recalled (and suspected) there is none. I would say its probably a door problem, vac motor problem or vac problem. make sure the door moves and there are no vac leaks on the engine.
--
Chris

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Good evening,
ok I'll check the blend door... where is it located? I'm guessing it is on the passenger side, below or behind the glove box... How do I check it?
I looked down by the passenger front door jam and under the glove box and saw one small vaccuum line connection.. it was in place and not leaking air.
suggestions?

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On Thu, 29 May 2008 18:03:09 -0500, jo wrote:

the blend door is on the heater/ac box under the dash (the black box close to the carpet) you will see a arm on the box that should move when you select hot or cold. there are a couple of these on there one moves the air from the dash to the floor to the windshield. the other is the blend door make sure they both move with the controls.
--
Chris

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Does the box open, so the doors are visible?
Someone else mentioned that a low freon charge could cause one of the two units to blow warm, and the other cold. does this make sense? Seems like if the charge is low, it would make both not work well.

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On Fri, 30 May 2008 17:51:19 -0500, jo wrote:

If the charge was low i'd suspect both systems would perform equally poorly.
there are arms that are visible you will see a rod connected to them on the outside of the box. the box does open but this requires removing the dash, and recovering the refrigerant from the a/c system to remove the box before it can be opened. I'll post a picture of one tomorrow.
--
Chris

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Thankyou! I just looked under the glove box and found one vaccuum line, and the box itself, but didn't see any rods or anything that looked like flapper valves. I look forward to seeing the picture.
jo
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On Sat, 31 May 2008 08:33:06 -0500, jo wrote:

alright jo i believe i found the doors you are looking for now they are no fun to get to. these links are photographed from the driver's floor board and looking up over the transmission tunnel. The top one (black on my truck) appears to be the blend door and our suspect on your vehicle (my assumption) i'd check the vacuum hoses ect for that door motor make sure they are on and all. in the picture of the black door motor you will also see a large vacuum connector you may also want to check and make sure none of those hoses are chaffed and the connector is seated firmly. the silver motor in the other picture appears to run the direction control. its right above the accelerator on the driver's side of the hump. for your information the motor you did find on the passenger side was the recirc door motor for the inside/outside air selection (max a/c on)
the is the panel/floor door it would appear and is a better picture of what a vac motor for the a/c doors would look like.
http://img520.imageshack.us/img520/7758/1003712da6.jpg
this is the blend door motor it would appear its way up there and i was only able to get a hand on mine then cycle the controls and feel for it to move.
http://img520.imageshack.us/img520/9707/1003711en7.jpg
i had hopped to get you a better picture of the actuators but that was the best i could do for ya.
--
Chris

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Thanks Chris.
I went out and looked for the items you mentioned and had photos of. I found the driver side and passenger side vacuum tubes. It was apparent that the two visible ones, (max ac and floor) both function fine... in that they shift and blow air from the correct vents... whether or not the max ac vent door is moving properly or too much I'm not sure.
I took some more photos and added some comments, that may be interesting to look at. I'm still stumped as to how to find the other vent door actuators / vacuum lines and also why the ac tubing in the engine compartment is so hot...
Check out the file and images at this link..
http://whatnotsnthings.com/item%20images/truck%20ac.html
jo

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On Sat, 31 May 2008 18:16:18 -0500, jo wrote:

might be time to beak down and take it to the shop. the picture of your cluster of vac lines is in the area of the blend door motor like i said its up in there. you can lay your hand on the motor and "feel" for when it moves. but it would be difficult at best to get to. as far what's hot and what's not its hard to say without a set of guages.
--
Chris

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