ac high pressure sensor

[ktbtrucking]

hello,

have fan set on high speed all the time
under insite it shows air conditioning pressure switch ON
All the time, does not matter if air condition is on or off
checked solenoid(good), jumped high pressure switch no effect insite says on
disconnected low pressure and compressor does not start
cant drain the system but bought high pressure and also connected
it is always On under insite, also I have the 11v on the switch harness that goes from switch to ecm
any thoughts?
it is volvo vnl 2002 with cummins isx