Did the Heater Treater thing to my 01 and now I have no temp control. I have hot or cold and nothing in between. I can watch the actuator motor turn the blend door from pin to pin when adjusting the temp control switch from one side to the other. Placing the switch at top dead center is the break point. One notch either way and it goes full to hot or cold. I haven't seen this problem on any threads and was wondering if anyone has any ideas. Don't know if this relates but I can also hear my ac compressor switching on and off when it shouldn't.

 

Your blend door problem is a new one for me but on an '01 I think the the A/C is on in every vent position except off.
A lot of people do this> http://dodgeram.org/tech/repair/HVAC/Defrost_AC.htm

 

Thanks, I may look into doing this. My feeling is that because of the other problem the computer doesn't know the position of the temp control know thus causing the compressor to kick on. I'm waiting for an email from Heater Treater to see if they've run into this before.

 

That's not it......the AC compressor runs in every position except for the two vent positions.....the ones that show the arrows pointing at just the feet and just the face.
I know that there was someone on here before that had the same problem as you do....possibly several years ago. Unfortunately, I can't remember the solution to the problem. Try a search, it may come up with a hit.

 

The 2001 Ram truck only runs in the "AC", "Max" and any "Defrost" positions. As for your problem I would double check the installation of the heater treater but failing that being the problem the blend door actuator (little motor on the bottom) is most likely your problem. While the actuator position is controlled by the temperature **** it uses feed back from the actuator. If that is not the problem it does say that the controls are not individually replaceable, what that means is you can't buy just one control you have to buy the whole thing, but you could get one from a wrecker and change just the temp control portion. If looking at a wrecker the early 2nd gen truck didn't use an electric blend door actuator they used a cable driven one so make sure you get the right one.

 

If you end up needing the control panel piece, and do not have power heated mirrors, I have a good spare one...