Need mute for radio

I recently got my new gps (a nuvi 360) after my Roadmate 700 got nicked from my car. I would like to have my radio/CD player go into mute mode while the voice directions are being conveyed. I also have a radar detector that gives voice prompts. I would like to have some kind of a sound sensor that will hear the GPS and/or radar detector and mute the radio until the voice prompts are over.    Is there some device that is available to do my trick or do I need to do some more research on this topic and device something myself? Without that, if I hear the radio at a good enjoyable volume, I cannot hear the GPS prompts.

Any information/advice/tips are welcome and thanks in advance.

If the nav does not have a mute output wire, you can use a toggle switch to connect the cd player's mute input to ground.  If it does not have a mute input, you can put a switch inline on the accessory wire of the radio, which will turn it off while your nav gives directions.  When connecting hands free kits to a radio without a mute input, you can interrupt the accessory wire with a relay.

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My ex once told me I have a perfect face for radio.

Thanks for the response, but I don't understand what you meant by putting a toggle switch between the radio's mute input and ground. Am I supposed to hit the toggle switch each time I hear the nav or radar make prompts? The purpose of what I am trying to do is to automate this process without me hitting any switch. I already have a mute button on my radio.   My nav does not have any wires coming out of it, its just a portable unit (Nuvi 360). The only outputs I have is headphone and audible sound. I was wondering if I could use the headphone output to connect to something where a signal sensed would switch on a relay or something. Just never did this before and would like to know if someone has a good idea. Thanks.

It won't be easy, but it could be done... As the headphone output turns the internal speaker off when something is plugged into it, you'll have to open the unit(s), and get your signal directly from the speaker terminals. This will most likely be a similar process for both the RD and the GPS.

You will need to build something (and I'll see what I can dig up, myself) that will give you a ground output, to attach to the mute lead of the radio. It'll probably need to be some sort of analog to digital circuit, using AND or NAND gates (Do they even still use those anymore? Am I showing my age?)

As I said, it'll be tough, but I'm sure it can be done...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

I get it.  Dave is right.  Looks like you will have to open the unit to reach your goal.  There are some line out converters available that provide a remote turn on signal whenever an audio signal is sensed.  You could then use that remote signal to trigger a relay, thereby, interrupting the accessory wire to the stereo.

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My ex once told me I have a perfect face for radio.

geepherder is right... a LOC with voltage sense will likely be your fastest and easiest BY FAR method of getting this lead... Honestly, I wasn't even thinking about anything like that when I responded first.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

I really was trying to avoid having to open my units to solder/connect wires because whenever I park away from home or work, I like to remove the two devices and cables tethered to my units would be a hindrance to my portability (safeguard from theft reoccuring). Agreed that is the best, surest and most efficient way to solve my problem. However, I was hoping to get a device like a tiny microphone that is placed close to these units that I can leave in the car camouflaged. If I could have the microphone sense a voice and turn on a relay, that would be my perfect solution. They have VOR tape recorders, where the tape starts to record just as it hears audio. That is the technique I want to use. It surely isnt the best method because if I sneezed loudly, it would shut the radio for a second as well hearing the sound (not something I want to have) but would solve my problem of a wire-less solution. I have 2 old such VOR tape recorders, one of which I am planning to dismantle and use the circuit from if I don't find a better method. Thanks for the responses though, help is always appreciated here.

If you want to be able to remove it easily, you could use a quick release connector (a molex type plug from RadioShack would work) for the loc, which would mean you'd just have a cheesy pigtail hanging out.

Alternatively, you could probably use the mini jack to achieve the same means, but would have to amplify the signal first, to connect the loc.  Not an ideal solution- more of a "Mickey Mouse" way of doing it.

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My ex once told me I have a perfect face for radio.