If it's clicking then obviously the operating switch must be OK!
The clicking may be the relay coil operating but not actually putting power through to the motor. I'm not acually familiar with the circuitry, but hopefully you can get to the components and try to hear where the clicking is coming from?
The clicking may be power getting through the relay but a motor issue is preventing the window from opening. Again, I'm not familiar with the components, but you may be able to access the motor connector and check (with either a voltmeter or a 12v lamp) if power is coming through when the switch is operated.... if no power, but the relay can be heard clicking, then the relay is not switching the power through... if power, then probably the motor is duff (but you may be able to gently push down the window while an ***istant operates the switch and get the motor to work again for a short while).
If you do remove the door trim, but don't have any luck with the above, gently twist and shake the wiring while operating the switch to attempt to show up broken cables. Also unplug and check all connectors in there.
When a similar thing happened on my wife's car, it was because the child-proof isolator switch had been accidentally operated, but you probably wouldn't hear clicking.
Good luck and please report back.
