Car AC Issue

[mgsmithsky]

The AC gradually faded over a year ago and only getting around to looking at it now - as winter approaches !

Topped up the car AC this morning following the recommended procedure starting with a UV dye test and cannot see any leaks in the system.

With the pressure gauge attached the pressure reads 35psi but when the clutch is engage the AC compressor kicks in, the pressure drops to Zero and the High pressure line feels particularly hot quite rapidly. Switching off the AC thereby disengaging the clutch, the pressure climbs back to 35psi
Any thoughts ....
Thank you

[E-bmw]

You haven't got enough in & the compressor is being over-worked to get the pressure up, you need to take it to an AC specialist & get it refilled correctly.