Air con issues
 

AC compressor clutch does not engage when air con is turned on. Low side and high side pressures
Both at 80 psi
2009 xk

OFF pressure for AC should be above 100 minimum. Seems you need a refrigerant service. Low pressure prevents stuff from happening.

Yep, regas. Make a note of where the connections are (on the //R one is under the air intake) so the tech doesn't suffer. Takes about 30 minutes for the machine to do it's thing, then blessed relief.

and for clarity's sake (doesn't change your problem) our a/c compressors are clutchless.

How does one add refrigerant if the can pressure is not 100lbs of pressure?

Cuz refrigerant is introduced on the LOW pressure side while the AC is in operation. Even if there isn't enough (or any) compressor action, there is still enough oomph to get some pressure into that side, then when the little bit is introduced in kicks in the compressor and lowers the low side pressure. Since the XK compressor is a clutchless variable unit, it'll suck in all the refrigerant it can.
I searched all over the place to get an actual PSI figure of a can of freon, damned if I can find any info anywhere. However, 100 PSI in a pressurized can isn't unheard of anyway. Them little buggers are really packed with stuff.

OK I will give it a try this evening.

If this doesn't fix the issue, you may need the pressure valve thats installed in the compressor. Can be replaced separately from compressor. There is a TB for this issue.

Hi i've had the same problem on my 2007 and it's hub compressor problem. Look for if the hub iexist on your compressor.
good day.
Marc