Temp Mixing Problem

[Bernie]

I just bought a 2003 CTD Ram 2500 with 95k miles. Good truck, it only has one problem:
The HVAC temperature mixing doesn't seem to work. I only get full hot or full cold. The mid positions of the temp knob just produce whatever the last extreme of the knob I was at. For example, if I was last at full cold I get full cold all the way until I get to full hot.

Suggestions?

 

[Ducman82]

sounds like a bad blend door to me. or the control head is on the fritz

 

[MScheiper]

Welcome to the club:{ Mine on the 04. 5 does the same thing. Seems to do it mostly in the winter months... . althought I don't use the blend much in the summer. Lot of posts on here about bad blend doors and some that have had the hinge tab broken off and found its way into the blower! My '06doesn't seem to have any problem at all and works flawlessly.

 

[Bob4x4]

Welcome to the club:{ Mine on the 04. 5 does the same thing. Seems to do it mostly in the winter months... . althought I don't use the blend much in the summer. Lot of posts on here about bad blend doors and some that have had the hinge tab broken off and found its way into the blower! My '06doesn't seem to have any problem at all and works flawlessly.

You are thinking about the recirc door issue

the doors use servo motors in the 3rd gens the motor failures are fairly common I have not seen many blend door failures but some servo motors and control heads.



Bob

 

[Bernie]

So I stopped by a semi-local dodge dealer, and they were no help at all. Anybody have part numbers or suggestions to troubleshoot the problem accurately? I don't want to take it all apart, to find out the part is two weeks out, and have to put it all back together, and repeat when the parts come in.

I understand the possibilities are:
-Servo Motor failure: Doesn't make much sense to me becasue I get full hot or full cold. If it failed, it seems like I wouldn't get any control.
-Blend door failure: Again, I doesn't seem like I would get the extremes. If it works like I think I would get what ever temp it was at when it failed.
-Control head: Not really sure how to diagnose. Any suggestions?

 

[Bob4x4]

The part# for the motors,all are the same no matter what door is

4885206ab I think they are right around $30 retail



Bob

 

[Bernie]

Not Sure How To Get To HVAC

So, Its summer and this isn't a huge problem right now. But, soon it will be. So, while installing the Sat radio, trailer brake controller, and a few other items I decided to see if I could get to the heater unit and see just what is broken.

Is there a trick I need to know? I had the center of the dash (pocket, HVAC controls, and radio) out and I still can't find an easy way to get to the heater box. The dash seems to be one big piece that seems to go in front of everything you need to get to behind the dash!

Suggestions?

 

[Bob4x4]

:-laf You must pull the dash out of the way to access the hvac housing.



Bob

 

[Bernie]

Crap. Any body got any good notes on pulling the dash out?