On my 99 RR HSE when the side view mirrors adjust down when put in reverse, the passanger side will not come back up. Any idea what the problem would be?

 

to test the passenger side mirror assembly to confirm, take off the passenger side mirror assembly
and plug it in the the drivers side inside plug (its behind the upper tweeter above the door panel)
and test, still don't tilt then replace. if it tilts with the right mirror assembly in the left plug
then a window switch pack may be needed.

 

Thanks for the help. Had to replace the mirror but at least with your help I knew where to start.