1996 Ranger Heat
 

my 1996 Ranger has a problem with the heat. for A/C it will only blow cold if only the MAX A/C is on. If i turn it to A/C then it blows HOT air out. Then for Heat is winter time. It only has HOTT!!! HEAT. The middle knob does nothing. I tried doing this blend door fix with drilling a hole in the acuator and putting a nail in it and all that..and still didnt work...anyone else have any suggestions? thanks

Sounds to me like its the controler or vacuum supply/hoses controlling the mode doors.

Rich