Good afternoon,

Have a 1999 GMC 5.3 L Sierra 1500. It sat for a couple weeks with the positive battery terminal disconnected. Went to drive it and A/C is like warm and not getting cold like it used to. Have tried to following remedies with no luck. Got to the end of YouTube and Google looking for answers. Any suggestions ? Thank you in advance.

1) Purged to Freon recharge valves to expel possible air bubble.

2) Recharged the Freon
3) Checked all related fuses
4) Tried to reset of turning on blower fan disconnecting battery restarting truck for two mins and turning off truck trying to reset compressor.
Using this article
https://vehq.com/gmc-sierra-not-blowing-cold-air/

Still nothing. Blower fans works fine but do notice under the hood near the belt that when the AC is turned on in the cabin and just the fan is running every 5-10 seconds there’s an intermittent click as if something is trying to turn on but that’s the extent of my knowledge. When the AC button is off the clicking doesn’t occur.

Thank you for any suggestions !!