Avalon A/C button not lite No A/C

[cntscott]

I have a 2000 Avalon and the A/C button on the dash will not light when pressed. Also the A/C will not come on. I have checked the A/C and heater fuse in the cabin fuse box. Both are good. Could this be a fan relay problem? If it is how do you check the fan relays? Can anyone point me to the items that needs to be checked to get the A/C running again?

[csaxon]

Check the refrigerant. If it's low or empty the low pressure switch prevents engagement (won't turn on)

[cntscott]

Thanks csaxon, I get this checked first.