Ac not working on 2004 s430

You can't just add refrigerant. It has to be done a special way.

https://www.fixya.com/cars/r29878326-recharging_vehicle_air_conditioner

Check fuses and the AC electronic Clutch.

Does the vehicle have dual zone climate control, where the driver side and passenger side have different control? Sounds like a blend door issue on the driver side. Why did you replace the passenger side, was it blowing hot too when AC was on?

Rule one thing out.... make sure you're coolant reservoir is full

The compressor has a thermal switch, if it gets too hot in the engine bay, will turn off, then back on when it's cooled off.

the problems are most likely related sounds to me like the controler is defected replace the ac and heater head unit

check for slipping ac drive belt ( smell and noise )

When the ac is blowing hot, is the compressor working when the engine is running ?
Have you checked the system to see if it is full of freon ?

If it has dual zone temp. control it is most likely the heater control panel.

My 2003 Toyota Camry AC often starts blowing hot air and the AC light starts blinking. I don't know why the following process works, but it does. Using the temp selector (left) reduce the temperature all the way down to Max Cold and then push the Auto button. It will start blowing out very cold air. After a little while push the temp selector to the desired temperature.

Most likly this van has seperate controls for driver and passenger heat and ac controls.If its blowing hot air your heat is working.These controls operate differant dampers that are electonicly controlled.If the dials arent working they would cause this problem.

I had this happend to me on my 2004 2500 in july in S.C.I turned the key off and on 5-6 times and i have not had that problem again.