initiald15

Hopefully I can get some help even tho this tread was posted many years ago. I own a 2004 Lexus RX330 which came with factory navi system with the Mark Levingston stereo. The DVD player for the navi system had been broken for a couple of years and I never plan on buying another one. But a few weeks ago something happened to the volume control from the vehicle on both the nub on the stereo and the volume control from the steering wheel. The volume number on the screen does not even go up or go down. So no sound. Spoke with the dealer and some audio shop they thought that the stereo is broken. So either pay $1000 for a brand new or a $600 for a use one that does not come with warranty. I ended up decided to go with aftermarket stereo. Bough the hardness that use to connect with the factory amp and the panel to make it look as close to factory set up as possible. After hooking everything and thought I was ready to play some music or listen to the radio... but no sound again. So finally make the effort into checking the amp and turns out the amp had been burn out. So as I was planning to just run the stereo and bypass the amp, I can't to realize when my factory stereo is unplugged from the vehicle, it is effecting the controls on the navi system area. All the buttons are slow in respond and on top of that. The climate control does not work at all. It say no connection to air conditioning control. So i put the factory stereo back in place and plugged everything back. Everything work again... well... except still no volume. So here's my question: "If my vehicle has the factory OEM navi system which even the climate control is control from the screen, does this mean I cannot unplug the factory OEM stereo system? Or is there another some kind of harness kit that I can buy in order to be able to install an aftermarket stereo and it won't effect everything that goes on up top on the navi screen?"