Car Stereos: Troubles with car audio set up, sony head unit, premium sound system

Question
I just bought a sony deck and am trying to install it into my 96 Grand Jeep Cherokee. It plays the radio, but when we put the cd player on the music doesnt come through the speakers. We can hear it a little bit in the sub but there is no sound at all in the speakers.

Thanks.

Answer
Hi Danielle,

Sorry about the delay in answering your question.  This is a common problem in Jeep and Chrysler vehicles, and it's a very easy fix.

Your Jeep is probably equipped with an Infinity premium sound system, which includes a factory amplifier.  The amplifier needs to be activated through a wire in the radio plug.  Most adapter harnesses sold for this vehicle use a solid blue wire for the amplifier activation.  

On a Sony head unit, the solid blue wire is a power antenna wire.  That means it's active only when "tuner" is selected as a source; when you switch to CD or auxiliary sources, the blue wire loses power.  The solution is to connect the blue wire in the adapter harness to the blue/white wire in the Sony radio plug, instead of the solid blue wire.  This will keep the factory amplifier turned on no matter what source is selected on the head unit.

Hope this helps!

Brian