1995 Lexus ES 300 Air conditioning

It probably needs more freon

Refrigerant Capacity 1.65 lbs.

Disposable canister method:

Connect a suitable refrigerant dispensing valve to refrigerant can, then connect manifold gauge set to system.
Connect center line of gauge set to fitting on container valve.
Purge air from center line by loosening connection at center fitting on gauge set, then slightly opening valve at container for a second or two. Retighten connection at gauge and close valve on container.
Open manifold gauge set low side valve and allow refrigerant to enter system. The refrigerant can must be kept upright if vehicle low pressure service gauge port is not on suction accumulator-drier, or suction accumulator fitting.
When can is empty, close valve and remove can. Connect new can, open valve and continue charging until correct weight of refrigerant has entered system.
If system stops drawing refrigerant in before system is completely charged, start engine, turn A/C on and operate blower at high speed until remaining refrigerant is drawn into system.
When charging is complete, close valve at container and run engine for approximately 30 seconds to clear lines and gauges, then close low side valve on gauge set and disconnect refrigerant can from center hose.

I put gauges on system.High side was purging between
400 450 psi.Let some freon out temp went to 46 degrees from 60.Decided to evac system.when I put freon back in,high side is coming up but low side is not.Now temp is in high 80s.I noticed in your first reply you did not mention to turn engine on but only when it needed more charge,is that correct.Am I doing something wrong with the procedure

The AC has to be running-sounds like its overcharge or it still has air in it-