A/c Issues

[golfballs]

I have a 2000 Gmc Savana G2500 5.7. My a/c wont work and i need advice on how to solve the issue. My compresser will not go on so i tried to add r134 and the guage states that the pressure is 70 and the gauge needle is in the alert area of the gauge. The gauge is a cheap one that comes on the the caqn of gas. On the canister that holds the low pressure port for charging there is a switch that i unpluged and bypassed and when i did that the clutch started to spin but i didnt here it engauge the compressure. Could i have other issues than the switch ? I dont know if the switch is bad or good, maybe the switch is working but is cutting the power to the compressure because of pressure issue ? If that is the issue wouldnt the compressure work when i bypassed the switch.

 

Thank You For Your Advice !!!