Haven't seen this thread elsewhere. The F150's (2000 & 2003) had an air filter in front of the AC coil to filter out internal "stuff" (dog hair, dust, etc.) Option which was installled buy cutting into the return air unit under the glove box.

Does anyone know if these are on the SD '06 Diesel trucks? Can you put one on if you want to? They really helped during allergy season if you have been down that road . . .

 

If it can be done you will probably have to get the parts from an excursion ?

, Craig.