Passenger's Side Only A/C Not Working
 

Hello! I have a 2002 RX300, and I've been having some problems with the passenger side A/C recently. The problem started when I was starting my car after it had been parked in the parking lot all day, and it started fine, but I noticed the A/C section of the screen didn't come on, but the A/C seemed to be working fine. So I restarted the car to see if the screen would come back on, but it wouldn't start again! I tried a couple of more times while holding the gas pedal down while cranking the engine, and I was finally able to get it to stay running, but it would only stay running while the gas was pressed down. I was able to get it to a repair shop and they said the fuel system needed to be cleaned, so I got it cleaned and it seems to be running fine now, except for the passenger side A/C! Also, there is a hissing noise that seems to be emitting from the A/C vents when I turn the engine off, which I have never noticed before. I was wondering why this could be happening and if that incident could possibly be related to the problem with the A/C?

Thanks! :)