My front driver side window wouldn't go down. I thought the regulator was busted so got a replacement. But when I tested out the new regulator&motor by connecting it to the main switch, the same thing happened (it would go up but not down). I suspect the main power window switch is defective since whenever I tried to lower that window, I heard a click from the switch but no power to the motor. Has anyone experienced this problem? Is there something I can fix without replacing the main switch assembly? All other windows work just fine though.

 

The main switch is known to go bad. Just find one at the wreckers for cheap, or order one from courtesyparts.com