Originally Posted by Veloce
Thanks for the quick replies.
This is the best explanation I've seen on stereo installation.
But, if I can just put in the Schosche harness (with red/yelow switch), why in the world does Crutchfield say it won't work with factory Infinity system (w/nav), but will work with the basic system? When I've read posts on stereo installation it has not been clear which type of factory system is being replaced.
If you want to test it, just go to the Crutchfield site and input a car w/o Nav/Infinity and the identical Crossfire w/o Inffinity/Nav system. I can't explain it and neither can the Crutchfield CSR (Customer Service Representative). The system I'm eyeballing is the Pioneer DEH-P7000BT.
There are 3 types of factory systems: Base system, Infinity System w/o Nav, Infinity System with nav. The base system doesn't have an extra amplifier -- the door speakers are powered by the head unit amp. So you don't have to worry about any amp to bypass -- its just a regular speaker level connection to the door speakers just like any other stereo install.
The infinity systems have the amplifier underneath the passenger floor, and add the 6 1/2" dual voice coil low range speakers behind the seats. So the speaker level outputs from the head unit don't go directly to the speakers, they go to the amplifier as I've described. There doesn't appear to be many differences with system between the nav and non-nav infinity head units besides a few extra wires at the head unit (GPS antenna, speed pulse wire, etc). The audio connections should be the same between the nav unit and the regular unit.
I suspect that Crutchfield probably thinks its a bad idea to put the amplified head unit signal as the input into the amplifier, which is why they say you need to bypass the amp. But considering this is how it's done in the factory system, it shouldn't be a problem.