99 explorer auto temp control problem

[johnsimas]

will not heat or cool in auto position.fan switch only works in high position and when selected manually heat and ac work.

 

[bobflood]

will not heat or cool in auto position.fan switch only works in high position and when selected manually heat and ac work.

Do a search on "auto temp control" and you will find many threads on this subject. Fan just working on "high" usually means blower resistor, but I think the auto system has another device that controls fan speed.

 

[BrianDye]

Same thing as mine did and many others.

Its the blower motor controller/resistor. I ordered one on RockAuto.com for about 60$, and it takes a good 30 minutes or so to replace it.