2nd Gen Non-Engine/Transmission constant heat

[BSmalley]

I have a 2002 CTD 2500. It is not driven in the winter unless its an extreme emergency. This spring I have discovered that the heat will not shut off. The blend door moves with the selector from floor to dash to defrost. fan works just fine. However, no matter where the temp selector is positioned, the vents blow hot air. Even witbh the system set to off, it still emits hot air. I checked to see if the knob was stripped but it seems OK. Was rather uncomfortable today driving 3 houirs to pick up a new to us 5th wheel camper with the outside temp in the 80's....Any ideas or suggestions of what to check.
Thanks,
Bill

 

[SAndreasen]

You could pinch the heater hoses of as a temporary fix

 

[GAmes]

Do a little forum searching. Not long ago there was a link posted for a fix for electric operated doors.

 

[petersonj]

This spring I have discovered that the heat will not shut off. The blend door moves with the selector from floor to dash to defrost. fan works just fine. However, no matter where the temp selector is positioned, the vents blow hot air.

The blend door is actually the door that directs cold dry air coming from the evaporator core to either pass through or around the heater core, or both , hence "blend". This is the door that your temperature control knob operates. The 2002 year model is a changeover year for the blend door to be controlled by cable or by an electronic actuator motor . You probably have the electronic actuator motor . It is likely that the plastic link (called an interposer) between the actuator motor and the blend door has cracked.

If you have the electronic actuator motor , you will find it on the passenger side of the truck on the bottom of the HVAC housing near where the firewall meets the transmission hump in the floor.

Contact "Heater Treater.net" with the fix for this problem for less than one hundred dollars, if you are willing to tackle the repair yourself. You can read about how to diagnose and repair the problem on this site.

I have done this repair on my 2002 truck after suffering with erratic temperature control (either too hot or too cold in the cab) for months.

Hope this helps,

- John

 

[mfurrh55]

Put a couple of valves on your heater hoses, and close it off to the heater core

 

[BigPapa]

Couple of good threads here:

https://www.turbodieselregister.com...Door-Motor-Could-this-cause?highlight=treater


https://www.turbodieselregister.com...-Blend-Door-USA-(Pic-Heavy)?highlight=treater

 

[GAmes]

Put a couple of valves on your heater hoses, and close it off to the heater core

I've thought about doing that for the last 18 years. However, there are times when I need the heater to aid my radiator when pulling a large trailer up a steep grade. Windows open, heater on high has saved me an overheated engine on several occasions.

 

[BSmalley]

Thank you all for the input. I just watched the videos for the Heat Treater and that seems like the direction I will go. I will post results of what I discover during the troubleshooting phase. Thanks to all again
Bill