A/c heating ?????

[LASVEGAS7.3IDI]

So my ? Is where should I start with my troubleshooting when I turn on the heat or ac system it only blows through the defrost vents no matter what is selected ie max ac or vent or ac any help would be greatly appreciated. Truck info 92 f 250 4x4 with a 97 powerstroke

 

[LASVEGAS7.3IDI]

So figured it out found a leaking line in the eng bay quick fix all better now

 

[subway]

you got it, these trucks default to the defrost if vacuum is lost for safety reasons