I have a 2005 FX4 and the last couple years the temperature gets stuck on cold or hot when the seasons change. Example: use AC all summer then in fall decide to use heater, spin the dial to Red but it stays stuck on Cold some how but maybe an hour later or next day finally switches over. Well this year when it did it it is finally stuck on medium heat no matter what i spin the dial too. Is the problem the Dial itself or something more internal?????

 

The dial seems cheap enough for me to replace. I had the speed control go bad and did the same thing.

 

So you can replace the dials independently?

 

Ok after looking over the net all day i found the solution. Guess its been an issue from trucks 2005 to 2008 and a TSB 08-23-6. This TSB replaces the 9L3Z-19E616-E Actuator. Even found a how to video:

 

couldnt find any info on my heater problem...i come here and find the tsb number and a how to video....i love this site....good job guys