Just noticed my A/C is blowing warm air and A/C button not light up. Any suggestions?

Most likely you have a bad switch. Check if the compressor clutch engages. You can see it by looking at the compressor belt pulley. If the clutch does not engage, the resons are etiher bad switch, bad A/C relay, or bad clutch. Each of these can be systematically chacked with an ohmmeter for proper functioning.

Or you could be low on refrigerant (it normally leaks a little to lubricate the seal). If you can, jump (for a few seconds) the pressure switch to see if the compressor clutch engages to troubleshoot this.

Surprisingly when I pulled the car into the garage I realized the A/C light IS on. And on further review the a/c fan does not seem to be running when the A/C button is on.

What happens is the cooling fan runs harder @ low speed then slower during faster speeds. but no a/c fan.

Any help?

the light only remains on when the fan is set at low speed.

There's also the possibility that the resistor block is bad. This works in conjunction with the switch to control the speed of the fan motor. It's located in the air duct behind the glovebox and is accessible via a cover on the duct. The resistors look like small coils of wire of different thicknesses and having different numbers of turns. They're in series, so a bad one can make one or more fan speeds inoperable. A bad resistor is easy to spot because the wire coil will burn in two.