Check the
"A/C Magnetic Clutch Relay"
it's under the hood to the left of the Radiator
it's feed from a 16 amp fuse labled "Guage"
it's controlled by the "A/C Amplifier"
located under the dash/glove box area by the blower
*** This relay controles BOTH the RPM's and the A/C Clutch
i have had these relays corrode on their connectors before,
just unplugging them & putting them back in cleans them if it's minor.
*seeing that you live in an area with salt in the air & high humidity*
Also, as
tonyconvert85 mentioned it might need a charge,
the way the logic in "A/C Amplifier" is setup,
it looks to see if you have the proper pressure in the system
BEFORE it trys to turn on the relay. GOOD Luck