It should work from either switch - if it doesn't then the winding gear may have broken - you don't mention the make & model of your car.
This happened to both front windows of my Golf - a mobile car lock specialist fixed them for me - About £50 for the winding gear and another £50 for his time each time it happened. The door speaker for the radio was pop rivetted onto the winding gear plate and had to be drilled out and re-rivetted. It took him about an hour to do the work.
Peccavi, July 2009
