There are three...the cycling switch is on the accumulator, the compressor pressure switch is on the hose manifold and the high pressure cutoff
switch is on the back of the compressor. Here’s a few parts from the manual, maybe it will help:
You must be registered for see images attach
You must be registered for see images attach
GM part number for high pressure switch:
You must be registered for see images attach
You must be registered for see images attach
Not sure which ones your 454 uses, but my 98 350 used these:
Cycling switch (accumulator):
You must be registered for see images attach
Compressor pressure switch (on hose manifold at the high/low refrigerant ports):
You must be registered for see images attach
High pressure cutoff switch (at back of compressor):
You must be registered for see images attach