[Garlicbreath]

here I am ripping the interior out of my 2003 jetta TDI and I find quite the contraptions under my carpet. There’s two circuit boards, and antenna, a box in the trunk, and three buttons on the plate by the ashtray. it seems to be hooked up to where a cd changer would be.

Does anyone know what this is for?

 

[guggles]

i think that box in the trunk could be for high to low signal conversion for a sub, or an aux adapter for the changer or aux input. Who knows what those other circut boards could be, maybe old mp3 player integration or phone or something like that idk.

 

[patbastard]

The USA SPEC box is a device you could use to connect your portable music player(or other player, which I'll lay out in a sec) through the CD Changer input on your factory radio.

The smaller circuit board looks like its an IR receiver for a remote control.

The larger circuit board is a three button board. Most likely play pause start.

If I were a betting man somewhere down the line someone had a DVD player, because the thick gray cord is a VGA connector, common on monitors at the time.

 

[XDleader555]

USA spec box is an aux to CD changer adapter.

The brown circuit board is a dc to dc converter. Most likely a 12v to 5v circuit to power the green board.

Green board is a bluetooth audio receiver. Someone soldered a custom db9 connector which leads to 3 custom buttons beneath the radio. Antenna is for the Bluetooth chipset.

 

[Garlicbreath]

That makes perfect sense. The brown board has a PC type power supply connector, the db9 goes to the three buttons and the other board (the three remote buttons are wired to the bigger board)

Is there another creative use for this setup now that I have a modern nav radio in the car?