Auto Air Conditioning & Heater Repair: air blowing only thru deforst ..., vacuum line, c programmer

Question
would anyone  happen to know where the vacum line runs too
from the intake undr the dash? the little round ac vacum harness on the ac and heater control unit or somewhere else.
ran a whole new vacuum line cuz it was missing, but not sure where it hooks in at. tore half my dash out almost grrrrr.. truck is a s-10 blzer 88 model

Answer
Scooter,

The new line should attach to the vacuum rotary valve mounted to the back of the A/C Control Head. It is possible that it stops in between at a vacuum delay valve, but I don't believe there is any other device (like an A/C Programmer) that source vacuum would go to. Is there an empty hole on the rotary valve? If so, put it there, and see if you have mode switching. Good Luck!