Rx300 Aux In Modification Possible?

[Topshelf]

Hey, I was just wondering if any of the Lexus electronic gurus have come across a modified direct aux in for the stock RX300 stereo system. I've done one on our C230 that basically modifies the tape portion so that it can be used for something more practical like a Satellite radio install. It isn't that bad at all, but I don't know enough about electronics to start hacking away without instructions. Here's the quick how-to for the MB version if it would be helpful to any EE's out there. And the link to it if you want to get more info and pics.

Link

Pictures

0. Insert tape into W203 radio while power is available to the radio.

1. Remove W203 radio.

2. Remove screws from top panel.

3. Remove screws from cassette mechanism.

4. Remove cassette mechanism.

5. Cut or desolder ground wires going to the motors on the cassette mechanism (there are two motors).

6. There is a trace to cut on the tape mechanism board and a surface mount resistor to remove in order to get pins 1 and 3 on the ribbon connector to be disconnected from the tape mechanism board.

7. Cut one end off of an RCA cable, preferably the type with twisted pairs of wires inside a somewhat hollow sheath.

8. Figure out a way to run that cable in through the back of the radio.

9. Solder the left channel wire to pin 1 on the tape mech ribbon cable.

10. Solder the right channel to pin 3 on the tape mech ribbon cable.

11. Close everything up and reinstall with the end of the RCA cable sticking out somewhere useful like into the glovebox or ashtray. You could maybe run it under the center console past the shifter to the center storage area or the cup holder spot.

Anyway, that's the mod. Here's how it works. You just switch to tape mode and the tape doesn't spin (because there's no power to the motors) and you don't hear anything from the tape (because the tape mech board is disconnected from the output going to the radio's main board). Instead your input goes through the RCA's into the radio in place of the tape audio. The radio doesn't even notice that the tape is essentially "stuck".

[deadbolt]

Pretty easy mod. Taken one step further you could add a switch to choose between AUX of TAPE restoring the stock look and feel. Using a 1/8 stereo mini jack instead of the RCAs will give you the option of mounting somewhere with easy access and unobtrusive looks say the glovebox for instance.

Now if only I could tell the difference between the HVAC knobs and the audio knobs I'd be all set. I think a set of billet knobs are needed. 2000RX300

[TLJester]

Did you ever complete this Aux mod ?

If so, could you share any instructions/photos?

Thanks