it does not happen all the time, but it happens after driving a while and mostly on a hot day here in Arizona that AC stops blowing cold air. Air coming in coming feels like normal temperature air (Hot day in Arizona). Starts usually after stopping on red lights or drive-thrus. I can hear compressor clutch tries to cycle but weird noise comes from engine and RPM goes up little jerks and comes down. It keeps repeating until I shut off the car and turn back on.
Today when it happened again, I came back from work and made a small video of the clutch.
Please watch the video and advise if you guys experience that, I want to get some idea before I go to dealer or mechanic and start throwing money on it.
I would really appreciate.

This is my first post in this forum, so I have posted in the wrong section, please move it or tell me where to post.
thanks!

 

Have the pressure and vacuum checked. It can be independent or Lexus if you like. Chances are it is low on freon. IDK if these have dye in them from the factory but if it's low, it likely has a small leak somewhere. Often times it can be as simple as the Schrader valve(s) where they get filled.

 

Today, I noticed that 1 of the radiator cooling fan does not work. That is probably why AC stops working on idling. Now I am not sure if I need to change the whole fan assembly or there must be a way to replace only one fan or look for a switch or fuse for 1 fan?

 

Do keep in mind that the AC has a low pressure cut off. If it cuts off, it doesn't need the fan so it also is turned off.
By default if the AC compressor is on, one fan is typically on. But ya, check the fuses. That said it doesn't explain your issue completely.

 

Actually it does. When the car is in motion, there is air flowing through the condenser coil, and things work normally. But when he stops at a light with the condenser fan not running, there isn't enough airflow over the condenser to reject the heat from the refrigerant (and turn it to a liquid), which causes the high pressure switch to trip.

 

My reference was his stationary condition. It needs airflow to cool as you stated, therefore a fan needs to be on. But if the compressor is disabled, no fan is needed.

That said before replacing fan motors, check the fuses, verify they have power and if need be, disconnect the wire harness and manually jumper the motor to 12v supply.
Though one could do this by removing the relay and jumping the load carrying conductors with the ignition on to test the motor. This is by far the easier way to test the motor. If the fan runs, its not the fan.

That said, the fan draws a good amount of current. Do not risk melting the relay conductors by making the electrical connection in the socket, insert two short wires and touch them together outside away from the socket.

OR - pop the cover off the relay (it is likely sealed so not easy) and toggle the relay closed.