Good Morning From Detroit and its getting cold up here,I have a 2000 2500 CTD and my heater,vent,defrost mode is stuck in the defrost position,hot to cold seems to work fine,just wont switch from defrost to heat or vent,possible vacuum swith?

 

Hello,Dresserave, I had the same thing happen,went looking for the problem,ie; vacum,stuck valve,turned out it ws simply the **** itself was broke,it was craked inside and would just turn,hope it is the same for you!! Good luck Rick

 

That could also be a vaccum leak. The heater controls are designed to go to defrost as a "default" position when there is insufficient vaccum. Does your cruise work like it should? If it doesn't then there is a leak somewhere. There has been problems noted under the left battery tray.
Tom

 

I thought the same thing Tom,cruise works fine,I am leaning twords the actuator ,thanks for your input.

 

Not sure about 2000, but my 2001 cruise control is completely electronic and has no vacuum control.


Zino

 

mine did the same exact thing...Here's your problem i would bet. Their is a thin hard-lined plastic vacuum line that runs from the driver's side to the passenger side on the fire-wall...it's high up near the top...check it for a small hole or crack ( check it good, i used soapy water to find the hole on mine )...i fixed that line and everything worked again...same symptoms as u r having..