01 suburban ls, both left and right mirrors will only move up. To move them left, right or down I have to manually push them into position. the fact that they move at all means it can't be a fuse or problem getting power to the switch. The fact that both mirrors will move up, but not any other way leads me to suspect the four way switch on the drivers door.

Questions:

1) Does that sound reasonable? Anything I'm missing?
2) Any idea how to replace (I haven't removed door panel yet, it's probably self-evident once I do, I assume).
3) Do I need to disconnect battery before doing?