What is the switch called that turns on the max ac or norm ac called not

[peachykissez]

the pressure switch 94 gmc sonoma? the compressor wont kick on when the knob is turned but if you hot wire from the battery it works i cant find that console switch not the knob
its the part that the vaccum lines hook too behind the knob

 

[Eric F]

are you meaning the low pressure cutoff switch? If you hotwire that, the compressor will force itself to spin.