A/C compressor won't engage

[1993ford]

Forgot to identify that I have a 1993 Ford Explorer. I just posted an a/c conditioner compressor question. The newly installed compressor won’t engage, I alsojust upgraded the freon system. We are looking at installing a new pushin a/c switch in the dash in hopes that this solves the problem. If this fails where do I go from here? Is there something cheaper to explor before pulling the dash out to install the new switch (by the way, the light goes on when the old switch is pusshed in , but nothing happens. I do not get any cold air).