2004 lexus rx330 w/ mark levinson and nav

Apparently the factory radio is tied to the navigation and the A/C fan controls. There are 3 or 4 plugs into the back of the radio. If the plug that has 2 wires is unplugged the A/C and Nav do not work on the separate touch screen. The 2 wires read approx. 2.4 volts each whether plugged in or not. These are likely a data type connection. I'm hoping someone on these forums might have found a way to replace the radio on these vehicles. My customer wants a new amp and a new radio, but short of relocating the stock radio, we aren't sure if this will work. Any info appreciated. Thanks!

Have you tried the Club Lexus site?  A lot of good info there.  ( Been finding a whole bunch of good tips for the wifes SC430...    )

http://www.clublexus.com/forums/esp_search.php?query=+radio+replacement+rx330&ref=esp-nav-bar&type=all

Soldering is fun!