SVXdc wrote:Tying up a loose end...
Originally Posted by trabbic
I bet this would work with our radio's, because when I was playing around with the pins on the back of the stereo to get my steering wheel controls working, the stereo muted and the display indicated "CALL"
Trabbic accidentally discovered the "cell phone" audio input on the square, 8-pin connector on the rear of the factory HU (what I've been calling the "subwoofer" connector, though it also includes the wires for A/C control and steering wheel "satellite" remote buttons).
When you connect pin 3 ("TEL ON") to ground, then the HU mutes whatever audio source it was playing, the HU's display shows "CALL," and a mono audio input on pins 1 and 5 ("SIGNAL + -") is routed to the radio's front speakers.
Using pin 3 is a much cleaner and simpler way to mute the radio than simulating the mute button from the steering wheel. If you can route the audio output from your Bluetooth phone kit into pins 1 and 5, so much the better.
Note that no connections are needed to the 14-pin speaker/power connector (unless you want to tap +12V, ground, and maybe illumination from there).
The only catch is you need to find male and female square 8-pin connectors to build a plug-and-play adapter.
See this thread for more technical details (they were attempting to hack this into a stereo Aux input, but it's not very desirable because the HU mucks with the EQ and volume levels):
AUX in on a Stock '05 Head Unit w/o Silent CD (The Project)
The phone input disappeared from the connector on 2007 HUs.