Hi everyone, I bought a 2002 Lexus IS300 that came with an after market radio. The car is fully loaded, it came with navigation (oem) , my problem is that it doesnt work. When I put the key on the on position the screen pops up and it displays the Lexus logo , then it just shuts off. I know that the oem nav only works with the stock radio based on what Ive read.Does the stock amp have anything to do with it? My car is missing the stock amp and I'm not sure if that to needed to. Just today I bought the stock radio and connected it to see if it'll work but nothing happened . Same as before only the Lexus logo shows and shuts off. Can someone please help , I've read similar topic like some swapping out their stock radio for an after market one and that encounter the same problem however my car came with an after market radio so I dont know what am I missing

 

do you have the dvd drive in the trunk?

 

Yeah I still have the dvd drive in the trunk.

 

I do not believe it will work without the factory radio

 

I agree I don't think the aftermarket radio will work with the factory nav system. Did you install the aftermarket radio or did a reputable installer do it? I'm looking at the wiring diagram for a 2004 IS radio with nav and I"m not seeing any connections from the radio to the nav ecu directly. Seems as though everything goes through the Amplifier in the dash.