I have a 2005 SC and when recently washing the passenger side mirror, i "tweaked" it and now you can use the inside adjustment to move the mirror from side to side but the up and down function on that side does not work nor the downward mirror adjustment when putting the transmission in reverse. The drivers side mirror continues to operate in all functions.
Have you tried tweaking it back a little. It might just be out of range for the motor to pick it up. Worth a try.
04 SC 430 White Gold Crystal w/Saddle, tinted glass, 25mm in the front. 35mm in rear, chrome stars (twisties), black emblems, debadged grill, Tein S springs, Injen Intake, wind screen, Lexus Aluminum Sport Pedals, navtool, rear camera, mgp caliper covers.
SOLD 07 ES 350 Obsidian w/Cashmere
2013 Prius 3 Blizzard Pearl/ Grey interior w/black pin strip, Solar Sun Roof, Appearance Package, XM Radio, Nav.w/back-up camera 17" black chrome rims, tinted windows, door edge guards.
Do you hear the motor run when you attempt to adjust it? If so, you've probably damaged the gears. Either way, Poqman's suggestion will get the necessary parts for you. I'm not real familiar with the inner workings of the mirror, so I'm not sure if there is something that could have just been knocked loose when you washed it. Worth checking it out though.
Here is the fix for my 2002 SC430 mirrors not adjusting. Pull down from the top of the housing, above where it says security.
There are two connectors one black, one white. Unplug them. Re-snap them back into place. The mirrors now adjust left, right, up down and go down when car is in reverse. In the LS forum the owners had to clean contacts to get the mirror working. On the SC I found no contacts even though I unscrewed two little screws inside the housing.