Cab HVAC Temp Problem

[Bernie]

OK, I posted about this once before and the answer I got didn't make sense to me. I have the following problem on my 2003 Ram 2500:



-My HVAC temp is 100% hot or 100% cold

-Same regardless of fan position

-No odd fan noises

-A large amount of heat (or worse, cold) still flows when the system (fan) is in the off position. The temp adjust still has an impact with the fan off as well.



The answer I got was "blend door". However, when I read the posts about the blend door what I could tell was a broken clip, that prevented any change and was accompanied by blower motor noises. My system can change, it just can't do mixing of temp.



Thoughts? I want to have a pretty good idea before I go digging in to the dash to find it.



PS- What a stupid design that you need to remove the dash to get to HVAC stuff.

 

[Bob4x4]

OK,

PS- What a stupid design that you need to remove the dash to get to HVAC stuff.

Have you ever worked on another model that was easier?



Bob

 

[seafish]

I just got my 2005 back from the dealer today for the same (and one additional) problem. The temp control started blowing warm air ONLY when turned up the whole way, otherwise it was cold. Also, however, the recirc/vent was STUCK on defrost, no matter where you put the knob. NO noises, no clunking. They diagnosed and replaced the HVAC "control head", which is apparently what the knobs hook up to behind the dash; Now, all is well and works as it should. I believe it is possible for only one half of the control head to fail, as each side controls a different function. maybe only part of your head is bad. Overall, the HVAC system in our trucks is extermly complex, with servos and moptors that actuate SEVERAL different blend doors. (even more so, I think, with the passenger/driver side climate zone models) Thankfully, the repair was covered by the MAX care extended warranty that I bought. ALSO THANKFULLY, my local dealer has a GREAT truck mechanic who himself drives a 3rd gen CTD. Oo. Oo.

 

[Bernie]

Have you ever worked on another model that was easier?



Bob

YES! Every other machine I have owned, with the exception of my 95 Ram!

 

[MAshley]

Not really hard, just unbolt the entire dash, steering wheel, electrical connections, covers and trim pieces and the Entire dash, oh say 150lbs worth comes out hehe



I replace the inside and outside door that fell on the fan causing no air to pass... . While I was there I also replaced a bunch of other doors.



4 hrs latter I was done.



But your issue sounds like the controls not the doors.

 

[MChildress]

This is going to be the first model I have had to work on. Mine went south this morning no defrost/no floor heat just blowing out the front vents. Still have control over air temp but sounds like that will go south soon. Will be first vehicle I have ever had to rebuild the HVAC system on.