HELP! AC coolant refill valve, where???

Have Yukon XL 2001

AC quit working yesterday suddenly. I am sure I know where the high pressure valves are located but I cannot find the low pressure.

There are two valves on the tubes entering the condensor. I hooked my guage and am getting a high reading...cannot locate the low pressure!

Can someone please tell me where it is located on this vehicle...getting frustrated at my attempt to figure it out...

Was going to recharge...please help!

Thanks in advance


Dorado

High and low pressure valves are located on top of the compressor