Used car with a mp3 player jack mystery

[Reply]

@Really_Not_All_That_Bright

It might be a 3.5 mm plug after all. They come in surprisingly variable sizes; the OEM jack in the dashboard of my last Hyundai would accept any 3.5 mm plug but none of them fit quite right and I would only get mono audio output unless the plug was seated “just so.”

Are you sure it wasn’t expecting a three-stripe/4-conductor plug, the ones where the last one is used for a microphone or inline controls? Phone connector (audio) - Wikipedia

[SmellMyWort]

@SpyOne

My LG cell phone has a socket for an earpiece with speaker and mic that takes a plug significantly smaller than the one used by iphones.

I have seen devices that took power through a plug that looked a lot like a earphone plug, but smaller.

There are any number of things that plug might be. Before I plugged it into anything valuable, I’d want to crawl under the dashboard and see where the wires go at least.

Yeah, I’m guessing some sort of hands-free set up for the previous owner’s cell phone.

[Isilder]

OP could try putting a signal onto the pins…

see the wiki entry for TRS … Tip ring shield… connectors for contact assignments.

If it is for audio input, AUX , the stereo system has a way to select it ? If you can’t select it what use is it ?
( It could be for a microphone for handsfree alternatively.)

And if it is for aux input, perpahs the tip can be reduced in size… or just replace it with a standard 3.5mm TRS

[carnivorousplant]

Check it with a voltmeter.

[Really_Not_All_That_Bright]

@Reply

Are you sure it wasn’t expecting a three-stripe/4-conductor plug, the ones where the last one is used for a microphone or inline controls? Phone connector (audio) - Wikipedia

Oh, maybe. I didn’t know that was a thing.

[scr4]

So this car stereo has a short cable hanging off of it, with something that looks like a 3.5mm stereo plug? And are you saying it’s too small to be a 3.5mm plug (i.e. it sits loose in a 3.5mm jack), but too large to fit into a 2.5mm jack?

Does it have the same design as a 3.5mm plug, i.e. looks like a metal rod with 2 plastic insulator rings along its length?