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Author Topic: Tricking a car radio aux input?  (Read 1522 times)
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Sorry if this is off-topic, I just usually get good answers here, and not sure where else to post a question like this:

I am using my car's auxiliary input (2005 Chrysler Pacifica) to play audio out of my android phone (could be ipod/iphone, etc.).

This works, except the way it works is the radio detects the audio signal and automatically switches between playing CD's in the multi-changer and the aux input.     This means when there is a pause in the audio, it switches over to CD, then back when the audio comes back.  Usually there is a delay.   It makes phone calls basically impossible.

So, I am wondering if there might be a way to fool the aux input circuit.

There is a video in, so one thought was maybe a signal/voltage could be applied to that line, since I do not care about the video in, thus hopefully tricking the radio to keep aux in active.

Otherwise, possibly there is a way to wire up some kind of circuit to make it think there is an audio signal, even during silence?

Thanks!
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Yeh, you will need to do some experimenting, but putting out a very low signal / very high signal in Hz should fool it and not generate noise (pick outside of the human hearing range).
What might really be happening is the device is not outputting during the period of silence (i.e. the headphones are actually going 'off').

Check it with an oscilloscope to be sure (or some other device that outputs audio via headphones and doesn't suffer the issue..

Might also pay to read if the stereo can disable that feature.
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remove the CD from the CD player ? (or is that too simple?)
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Nope, already removed all the CD's.    When it detects silence, it switches back to CD playing mode, instead of aux input.   So even though there is not actually a CD, changes back to that mode and says 'no disc'.
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Are you sure it is doing it by sound detection?  Most devices use a micro switch in the jack.
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I am pretty sure, since plugging it in does nothing.   It only switches when I push play on a song for example.
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Most video inputs detect if there is 75 ohm on the input line.
try putting A 75 ohm resistor on the video input and if that works you can build A little box with A switch to enable your input.

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