HVAC temp adjustment issue, 2003 Ram Diesel
#1
12-12-2008, 11:24 PM
Join Date: Dec 2008
Location: South Carolina
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
HVAC temp adjustment issue, 2003 Ram Diesel
I have an 03, 2500 Ram, Cummins Diesel, 4WD automatic.
The HVAC control for the temp seems to only switch from extreme hot to extreme cold. I have removed the glove box and most of my dash and watched as the servo/actuator thing moved steadily from one extreme to the other as I slowly adjusted the temp control dial. I even moved the dial one 'click' at a time and watched the servo/actuator thing stop at each graduation as I stopped moving the control dial. Unfortunately, none of this seems to do anything to actually modify the air temp coming from the vents. Sometimes it is just cold, sometimes just hot, and sometimes just barely warm, but regardless of what comes out of the vents, it stays at that temp for the duration of my drive. It is different for just about each trip I take, sometimes it is hot, sometimes cols... you get the idea. Anyways, I have visually verified that the motorized servo/actuator thing does work in conjunction with turning the temp control dial (works with the fan on as well as off). Is there something inside the box that is likely to be broken? Can anyone point me to an online resource or exploded view of the HVAC box that could give me an inside view before I try to take the whole thing apart myself? Is this a common issue with the 3rd Generation Ram trucks?
Thanks to all in advance.
The HVAC control for the temp seems to only switch from extreme hot to extreme cold. I have removed the glove box and most of my dash and watched as the servo/actuator thing moved steadily from one extreme to the other as I slowly adjusted the temp control dial. I even moved the dial one 'click' at a time and watched the servo/actuator thing stop at each graduation as I stopped moving the control dial. Unfortunately, none of this seems to do anything to actually modify the air temp coming from the vents. Sometimes it is just cold, sometimes just hot, and sometimes just barely warm, but regardless of what comes out of the vents, it stays at that temp for the duration of my drive. It is different for just about each trip I take, sometimes it is hot, sometimes cols... you get the idea. Anyways, I have visually verified that the motorized servo/actuator thing does work in conjunction with turning the temp control dial (works with the fan on as well as off). Is there something inside the box that is likely to be broken? Can anyone point me to an online resource or exploded view of the HVAC box that could give me an inside view before I try to take the whole thing apart myself? Is this a common issue with the 3rd Generation Ram trucks?
Thanks to all in advance.
Last edited by momosapien; 12-12-2008 at 11:26 PM.
#2
12-26-2008, 02:20 AM
Unfortunately, you most likely have a broken drive connector in the hvac unit. The actuator drives this piece of plastic that is splined to the blend door in the housing. The problem is that the actuator is stronger than the plastic part and the stops are not in the proper place. This allows the actuator to over-torque the drive connection in the door which causes it to split. This split may still allow some temp control but will be erratic as the pieces catch once in a while. Your dash will need to be removed along with the hvac housing behind it. An updated hvac housing should be installed along with all of the doors to make sure this does not happen again. There is a tsb for broken defrost doors but not for blend doors but they both suffer the same problem. Hope this helps.
