hvac door #3

ichoplin · 10-25-2009, 06:48 PM

I hate to start another "blend" door thread, but I haven't seen exactly what I'm looking for yet. I read a ton of posts about a recirc. door, but I don't think that is my problem.
I'm not really getting a full flow of air from any position, especially the floor setting. I can get a little at defrost and a little more at dash level.
I pulled the glove box and fan. The fan is working just fine. I watched the recirc door move w/ the control knob on the hvac panel. I also watched the levers move w/ the temp control knob. So I know that these two are working properly.
I read about a third door that is behind the steel plate in the dash. Should I presume this is the one that's broken? What is this door called? Is there anyway to get to it/disable it w/out removing the entire dash, etc...?
I read and watched the vids at Heatertreater.
Thanks,
Ian

ichoplin · 10-25-2009, 08:05 PM

I did some more searching and learned that the door I'm referring to is called the mode door.
So, is the mode door accessible w/out removing the dash?
Ian

WoodChuck · 10-26-2009, 08:01 PM

I've pulled my whole HVAC assembly apart and can tell you that the only one accessible without removal is the recirc door.

ichoplin · 10-27-2009, 01:45 AM

I saw the thread that shows a dash/hvac removal. Did you go through all that too? Is there anyway to do this w/out evacuating the a/c and coolant?
Just for giggles, I called a Dodge dealer in OKC and asked if they had heard of any recalls, etc for this. The serviced rep told me that Dodge/Chrysler didn't consider any of this to be a safety issue. I laughed and told him he was crazy. He went on to further say that all the other brands out there have the exact same issue w/ their own hvac systems. I find that hard to believe.
Ian

WoodChuck · 10-27-2009, 02:57 AM

Yes I yanked it all out just like in the pictures.

sag2 · 10-27-2009, 05:27 AM

I don't think yours is a Mega Cab, but if it is there is a screen to divert some of the air to the rear. If that gets plugged with hair and dirt it will restrict the flow to the front. You still have to pull the dash to cut it out, but you don't have to discharge the A/C or coolant.

MAshley · 10-27-2009, 05:01 PM

THis mode door as you call it controlls inside or outside air.... in my truck it broke and fell on top of the fan inside, so as the fan blew air the door basically block the air from moving around. some did get past but not much.

WoodChuck · 10-27-2009, 06:27 PM

Quote:

Originally Posted by MAshley

THis mode door as you call it controlls inside or outside air.... in my truck it broke and fell on top of the fan inside, so as the fan blew air the door basically block the air from moving around. some did get past but not much.

The door you're talking about isn't the mode door, it's the recirc door.

tschidas · 11-03-2009, 12:08 AM

In the process of repairing my 3500 Ram w/ poor airflow to the floor, found the recirc door broke (door shaft overdriven and twisted off) yesterday w/ limited access, blower and glove removed, unfortunately I continued on today as that door doesn't explain my primary issue, pulled the whole unit w/ great help of scbroder post, HVAC Removal w/ Pic's, in any case I press on and have found the furtherest left mode door also broke, going for parts tomorrow and attempt re-assembly, the only thing I'm still perplexed w/ the need for performing the Actuator Calibration Function and specifically the correct position of the new door in relationship to the motor? How sad is it I'm repairing a 2006 truck w/ problems and threads dated back to early 2000 trucks, I've nearly lost all faith in Dodge and most of the US automakers ability to acknowledge issues and design out flaws such as this!

sag2 · 11-03-2009, 04:17 AM

The HVAC control head "learns and knows" the door position by driving it until the motor stalls in both directions. It then knows the limits, and since it is a stepper motor it then counts the number of steps between the stalled positions, and can position the door anywhere in between, or at the stalled positions.

tschidas · 11-04-2009, 08:01 PM

Resolved my issues as described above, replaced Recirc door w/ upgraded assembly which included door and motor and now has hard stops, replaced Defrost mode door and coupler which had broken and assumed to have caused it to overdrive and break, once re-powered doors did self calibrate as advertised, total parts cost was $80 and 6-8 hrs of my valuable labor, no surprise parts were readily available as Dodge must do a lot of these repairs, thanks again to scbroder's post, HVAC Removal w/ Pic's.

AMink · 11-04-2009, 08:32 PM

Even after I got mine broken blend door fixed, the whole system still stinks. Loud fan, low volume of air, a/c is never that cold. I'm not impressed with the system. I am guessing my recirc door still works because there is a change in sound and air volume when I move it back and forth. Has anyone figured out if a bigger (better) fan can be installed to move more air?

ichoplin · 11-15-2009, 03:50 PM

Update: I finally "nutted" up and took my dash off this morning.
Found out my mode door is fine.
I learned that my Defrost Door is the culprit. I'm definitely at the point of no return now. I've still got the hvac housing in the truck and have not evacuated anything. Is there enough slack in there that if I loosen the bolts holding the housing that I can get to the defrost door?
After a pot of coffee and an early morning, I'm becoming a little weary of just taking even more hardware loose for fear of really getting myself in a bind.
Thanks,
Ian

ichoplin · 11-15-2009, 05:18 PM

Well, I got the defrost door out w/out having to remove the entire hvac assembly.
W/ some makeshift screwdrivers, I was able to remove enough screws to get the defrost door out. What a PITA.
Ian

***bighammer*** · 11-16-2009, 04:56 AM

Quote:

Originally Posted by ichoplin

Well, I got the defrost door out w/out having to remove the entire hvac assembly.
W/ some makeshift screwdrivers, I was able to remove enough screws to get the defrost door out. What a PITA.
Ian

I'm impressed. I looked at where all that was and chopped my A/C lines so I could get the whole thing out.