Im sure there is already a thread that answers this question i just haven't it so i thought id ask here. I just put in a sub and amp into my car which is a 2004 TL with navi i used the method of splicing the RCA's into the stock sub wires it works just fine except for when i put everything back together and fired it up i had the radio error i got the code and that works fine now its just that now the navi wont work at all. Theres just a little green message box that says please insert disc and the disc is inserted i pulled it out and put it back in numerous times and the door is closed. My question is could the amp to the sub be pulling enough power to make the navi stop working or am i on the wrong track? Any help would be great.

 

Here's what I would do to troubleshoot the issue. I'd disconnect the AMP and see if the NAV kicks on when you start the car. If it doesn't, then I'd say the AMP is drawing too much power. Did you match the ratings on the AMP to the factory AMP and the Sub to the factory Sub?

 

make sure the small door is closed too. There are 2 doors on the front. Even if the small door is barely barely open, you may not see it, but it won't like that. look closely at the small door.