I have a 2005 chevy silverado 2500 HD truck.
The exterior left side rear view mirror is not working properly. The up down button or
switch does not work but the right to left switch works. how do you take this apart and or
diagnose how to fix it. I am handy at fixing items like this but have never done it before
If your handy you should be able to pop the panel that the switch is located in, or remove the switch to diagnose if the switch itself is the issue or maybe the cable or mirror is stuck. Search the net on Chevy truck forums for some more assistance.
Before you take anything apart (which you'll probably have to do) push the button and lightly assist by pushing in same direction with hand power it might help free it up. It's not just frozen water in there is it?