Hi,
I also had a problem with my transfer indicator switch. My dealership wanted $90 for the part and about 1 week to get it. I had success with just cleaning the switch instead of having to buy a new. Just finished a write-up on it in case anyone's interested: Transfer Indicator Switch Problem with 4WD Toyota/Lexus Center Differential Lock
Thanks,
Clifford Arrow
http://monkeeworks.com