A/c Doa

I have an 01 Silverado 2500hd Quad cab. I bought it knowing the a/c didnt work. Since purchase i have tested the
freon= ok
high pressure switch = bypassed
only relay i could find under hood = Ok

When I place the switch to a/c the light come on however it does not send power( tested ) to the Compressor.

Does anyone have any idea what the problem could be!
The Truck does have Auto Climate control.

any ideas Would be great

FYI its an 8.1 496

did you bypass the low pressure switch? there is an IGN E 10A fuse that feeds the control side of the relay hot in run/start. see if thats blown and if its ok you might see if the computer is grounding that circuit out when you turn on the ac. put your test light across terminals 86 and 85. if it doesnt light then the PCM is getting some signal to keep it from kicking the ac on. if it lights check A/C fuse 10A its hot at all times. if thats ok jump the other side of the relay, 87 and 30, and see if the compressor kicks on.

Low presure bypased= nothing
All fuses ok
jumped relay=nothing happened

It does have climate controll do you think that makes a difference?