About a year ago the control for the side mirrors on the '01 lw300 started
to get ornery. If you jiggled the switches enough, it might work... mostly
not though.

Finally removed the switch module from the door and dismantled it. It's held
together with plastic clips that can be carefully released to pull apart the
switch. Cleaned off any dust and debris that had accumulated under the
'joystick' button. Cleaned the circuit board and actuator pads with a dry
Q-Tip first to remove any surface dirt. Then wet the Q-Tip with a small
amount of "Deoxit" and re-cleaned all the electrically contacting surfaces.
Put it back together and so far it's working like a charm.

Deoxit http://www.caig.com/ removes oxide from electrical contacts. First
used it to renew a relay that was no longer available. Was a simple fix!