Here is a short how-to for installation of an AUX-IN module to the factory radio in a 99 RL w/o navigation.
This is my personal step by step guide on installing the sound module. Although the whole installation is very easy, do it on your own risk.
What kind of a sound module is this?
It is a single AUX-IN module, which replaces the aux-in of the factory CD changer.
What do you need for this installation beside such a module?
Not much, maybe your best pal, some patience, dexterity, 20 minutes of your time and a wrench.
Before you start this installation, remove the disc changer magazine! Afterwards there won’t be any voltage available to take it out, so don’t forget it!
1. Turn off the engine and ignition. Apply parking brake.
2. Remove the carpet panels to the left and right of the console. Watch out for those clips! They sometimes do not hold on to the panels and might get lost.
3. Remove the select lever cover by pulling gently on both ends. The cover is mounted on four clips. Again, watch out for those clips! See the pale blue arrows on the screenshot.
4. Unplug the connectors and take out the bulb for gear panel illumination.
5. Remove the wood cover by lifting it up and pulling out towards back of the car. This cover is also mounted on clips (see the red circle on the screenshot).
6. Now we have access to the bolts holding the radio console. Unbolt the nuts with a wrench. Start with the both in front and continue with the both to the left and right of the console. See screenshots
7. The console is now ready to be taken out. Pull gently at the bottom and at the top. The console is hooked into the dashboard at the top. Be careful (blue arrows).
8. While taking the console out be very careful not to scratch the leather! The console’s edges are very sharp! See the red highlighted area. The blue arrows show the clamps which hold the console to the dashboard.
9. Now you have access to the cables from behind. Find the CD changer cable and unplug.
10. Plug in the AUX-IN adapter. Be sure the connection is tight. My adapter required to be grounded. I took the ground wire and wired it into the cigarette lighter. Follow the instructions attached to your AUX-IN adapter.
11. Find a place to put the audio wires out. I used the right carpet console. Later I will put the wires under the middle console.
12. You are done. Plug in a player (notebook, MP3, etc.), turn the radio on and switch to CD mode. The AUX-IN plays on CD01, title 01.
I tested my AUX-IN with my Nokia cel. phone and my IBM notebook. The sound quality with the Nokia phone was OK, much better than any FM transmitter. Then I hooked up the notebook and played an audio CD. Now the sound quality was very, very good. I was amazed.