The compressor isn't cycling properly. There is a sensor on the compressor that detects if the comp is turning when there is an A/C request ( you have the HVAC system set to A/C )
When this sensor tells the HVAC programmer module the comp isn't turning, the light will blink.
As to why we want to know what year, some systems function differently from year to year

Hot air flows through the air vents. A/C light is flashing. What is wrong?

At this age the hoses have probably failed. Professional leak checking and charge is required.

Try switching the clutch relay with another one in the same relay block. (under the hood.) Nine out of ten times that's the most common failure.