I tried to add an mp3 input to the stock stereo in my 98 bonneville as described at the link below:

http://bradgoldring.com/delco_auxin.pdf

Anyway, I have a couple of questions for anyone who might have tried this. First, when I was putting it back in, the lights in the stereo went out. I checked the main bulb, but it seems OK and besides, all the other lights are out as well. The stereo still functions, but you cannot see the screen. Any ideas where to look for the problem.

Also, while the mp3 input works, the stereo still wants a cassette in and rayaunning in order to play the mp3'*. Does anyone have a suggestion or a fix for this.

Thanks.

Well I had to go it alone and I thought I would document what I did in case someone else runs into the same thing.

For the light problem, I checked the car'* wiring and everything was fine. Then I checked the bulb and it was OK. The small circuit board that the light is attached to worked as well, so the fault was either in the ribbon connection itself or on the main circuit board. I didn't have the patience to check the main circuit board, so I rewired the light directly to the switched power lead at the main connector, with the ground wired to the stereo housing. Since I don't have a wiring diagram for the stereo, I broke the factory leads too the light to ensure I didn't back feed any other circuits.

Put it back together and it works fine. The only functionallity I have lost is the inability to dim the main display. You could tap into the dimmer circuit, but then it would not light unless the lights were on. I think this is a little bit better.

As for the MP3 conversion, it is complete and working fine, but I need to keep a cassette in the machine to make it work. No big problem I guess. I have been using a blank cassette to prevent ghost noise from the tape.

Overall, it isn't too difficult a job, especially if you don't bust the back light circuit in the process.