Bentley cont gt ac problems

2004 bentley CGT. AC does not work. Full charge. My gauge is reading a very high lowside pressure. It apprears this car has a veriable vein type compressor (clutchless). Can some one provide me with a system overview or possibly some common problems with this system which would cause the ac to not cool?

With the car running and the ac on, the pressure does not change. No increase on the high side and no decrease on the low side. That indicates the compressor is not pumping.

Obviously something is controlling the veriable compressor. Are the controls (sensors or switches) part of the compressor? Or is it an external module? Maybe a mix?

Everything is hard to get to. I would like to avoid removing the compressor if it not required.

Speaking of which, does anyone know the labor hours for rplacing the ac compressor?

Thanks
Daniel