I generally leave AC work to the pro’s, but I’ve got this 95 Tahoe that hasn’t had any issues in the couple of years I’ve owned it. I let it sit (for me to get around to fixing the brake booster) and now the AC compressor won’t kick in. Dash button lights up. Tried to “urge” it with a screwdriver to see if my clutch had too much gap but it didn’t respond. What should I check next before taking it in for a refrigerant/leak check?