GM-GMC: AC problem, gmc sierra, sending the signal

Question
I have a 96 gmc sierra. My ac is blowing air but is not getting cold. It's been re-charged. I have noticed that the recycle button and ac button both lights don't turn on. We've checked all fuses. We think maybe the lights not turning have something to do with it but we don't know what else to do. Please help. Thanks

Answer
It is possible that the control head is not sending the signal to turn the a/c on.  There are two ways to check that, one is install a scanner and look for that output or the other way is to replace it with a known good one and see if it works.
hope this helps