I want to start by giving credit where its due and that is to member ddalder, who I have not had the pleasure to interact with here and by all accounts may not ever have as I'm told he no longer visits this forum. ddalder is apparently an electronics wizard and perhaps a mechanical wizard as well. I would not have figured out how to do this without ddalder’s postings on the subject. In fact, I’m also giving ddalder credit for anything that I post here that I learned from him or otherwise ‘borrowed’ from him. I also want to thank and give credit to member kts0347 for getting ddalder to so descriptively write up a how-to on installing the CDX. Through the following thread,
viewtopic.php?f=13&t=11336
I was able to gather the knowledge I needed to complete this project. Thanks also to harofreak00 and others who answered some of my questions or supplied me with parts along the way. I want to make it clear at this point that the instructions in the thread at the above link are for those that do not have either XM or the CDX option and will likely be the most useful overall thread for installing a CDX. And while I highly recommend that anyone adding this option read the above thread, my write-up here is specifically for those that already have the XM satellite radio option and want to add the OEM CDX. That is essential to use my directions here, and is likely only for the later model Bonnevilles, '04-'05. If you do not have the factory-installed XM option in your Bonneville, you can probably stop reading this and go to the thread at the above link where he describes how to install it without XM. You may also find both helpful to your install.
Now for the disclaimer (credit to ddalder for this too...)
BEFORE YOU DO ANY OF THE WIRING WORK BELOW, DISCONNECT YOUR BATTERY! IT IS IMPORTANT THAT YOU USE PROPER TECHNIQUES FOR SPLICING INTO THE VEHICLE WIRING HARNESS. PART OF THIS INVOLVES MAKING CONNECTIONS INTO THE CLASS 2 SERIAL DATA BUS. FAILURE TO MAKE THESE CORRECTLY OR USING POOR TECHNIQUES MAY RESULT IN ERRONEOUS BEHAVIOUR WITH VIRTUALLY ANY FUNCTION IN YOUR VEHICLE. IT IS SOLELY THE RESPONSIBILITY OF THE VEHICLE OWNER, AND/OR THE INDIVIDUAL INSTALLING THIS OPTION TO ENSURE IT IS DONE CORRECTLY. NEITHER THE ARTICLE AUTHOR, NOR THE STAFF OR OWNER(S) OF THE PONTIAC BONNEVILLE CLUB FORUM SHALL BE RESPONSIBLE FOR ADVERSE EFFECTS DUE IN ANY PART TO FOLLOWING THE DIRECTIONS IN THIS ARTICLE. HAVING SAID THIS, EVERY EFFORT HAS BEEN MADE TO TRY AND ENSURE THE ACCURACY OF THE INFORMATION PROVIDED.
Onward. What may come as a surprise is that the easiest part of this project is the actual installation. The hardest part for me was getting all the parts. The older these cars get the harder that will be, but for now, if you know where to look (this forum included), you can find what you need. With that, let’s talk about what is needed.
In addition, you'll need about 24' of 4 conductor shielded wire, 20-22AWG. Some of it doesn't have to be shielded, and you're not going 25'. The way I routed it I used about 12', I just found it easier to buy one length and cut it in half. You can use any variation you want but you at least need the audio cable to be shielded. You're going to need a total of 7 conductors plus a bare wire that's part of the shielding. Shielded signal/audio cable works best for this. I used 22/4 that I picked up at HD.
You'll also need some harness wrapping tape or some other method of routing the cables together neatly. I prefer the flexible plastic conduit, and it's what I used for the most part, but did tape some areas. In this install you're just going from one side of the trunk to the other. Since you already have the factory-installed XM option, and the CDX is run in parallel with the XM module, all the necessary wiring is conveniently located across the trunk where the XM module is mounted. There is no need to run any additional wires up to the radio head unit.
Audio out, power, and serial data is all available there, and in fact, the XM module is powered from the same 10A fuse in the fuse block that is marked CD, so it's just a matter of tapping in to all the appropriate wiring at the XM module. Yup, it's that easy.
Starting Point
-----------------
Remove all of the trunk trim. It's ok to leave the floor carpet in place, but you'll need to remove the plastic trim closest to the back of the car, the plastic trim behind the rear seat and the two carpeted side trim pieces. There are a lot of electronics behind all of this trim, so use caution when removing it. Also, to get the rear plastic trim out of the way completely, you'll need to disconnect the air inflator switch and air line from it, if applicable.
The Harness
---------------
You can color code your wiring any way that works for you, here's a picture showing the pinouts and target colors:
Since I purchased my CDX from a supplier, I did not get a connector with it, so I had to purchase the connector. It came through with pigtails, but they were all gray as shown. If you got a factory pigtail with your CDX, you'll have colored pigtails. The pinouts are the same regardless of color. Just keep track of what is what, as outlined in the picture.
Before you do any terminating, determine what path you want to take with the harness so that you can get a decent idea of how long your harness needs to be. You can always shorten it once you get ready to terminate at the XM module, but you don't want to wind up short. Keep in mind you'll need an extra few inches for the chassis ground wire, so it's best to make your harness long enough to account for the ground and then cut the others back as needed. If you're using single conductors in your harness, this isn't as much of an issue; just make the ground wire longer.
I used butt splices for the connector and AMP tap splices on the XM Module end for the most part. Here's a picture of my completed harness.
I had thought about routing the harness up and over the top of the trunk through the channel that runs across the top edge of the trunk opening, but in the end, I opted for a more conventional (and accessible) route around the shock towers and along the top and back as shown below. That route required a harness length of about 12'.
The CDX
----------
Insert the threaded stud in the open slot on the right side of the trunk, as shown here. Notice the other two studs are already built in.
Close-up of stud and nut:
The CDX mounts to the bracket with 3 - M4 x .07 bolts and lockwashers on each side. If you got your CDX with the bracket you probably already know this. Mount the CDX to the bracket before mounting it in the trunk. Once mounted to the bracket, plug the CDX connector end of the harness into the CDX.
Align the bracket w/CDX onto the three studs as shown below, maneuvering the left side around the trunk sheet metal riser first. Mine was a pretty tight fit and I had to attach it to the studs in order of front to back; YMMV. Secure the bracket with three 10mm nuts.
Connections
---------------
IMPORTANT! Before you make any connections, disconnect the battery!! (see disclaimer above)
Disconnect the connector from the XM module and unwrap some of its harness as needed. Take note that the audio wires going to the XM Module are wrapped together separately within the harness. That makes it easy to determine which black wire is the audio common. Keep them separate and rewrap them the same way when finished. Avoid making all connections on top of each other resulting in a large bump in the harness. Stagger the taps instead. Make connections as follows, double checking all when finished. Note: All wires are connected in parallel (using tap connectors or splice connectors) except for the serial data wires, which must be connected in series with the XM Module data wire. For the series connection, cut the purple wire a few inches back from the XM connector. Splice one of your CDX data wires into the purple wire going into the XM connector and splice your other CDX data wire into the remaining purple wire from your cut at the XM connector. Here's a more complete wiring diagram, showing XM Module terminations:
Once all connections have been made, wrap it all back up with tape (or save this step for after testing), plug the connector back into the XM module and reconnect the battery.
Put your favorite CDs into the CDX cartridge. Slide the CDX door all the way to the left until it clicks. Load the cartridge into the CDX. Slide the door all the way to the right. You should immediately hear the CDX start going through the stack as it catalogs the CDs. I waited until the stack read was complete before proceeding.
Turn your ignition to ACC. Turn on the radio. You should either see the stack of CDs flashing on the display or solid depending on whether you waited for the CDX to do the stack read. The Pre-Set button on the steering wheel controls changes discs, the seek button changes tracks. The display should look something like the picture below when playing a disc. See your owner's manual for complete CDX operation.
Finishing Up
---------------
Once you've verified everything is working correctly, reinstall all of the trunk trim, including the new right side trim piece around the CDX and insert the plastic button through the trim and into the bracket to secure it. Here's what the new trim piece looks like.
Finished Project:
That's all there is to it. How easy was that? The wiring and install took me just a few hours, probably less time than it took to complete this write-up! Getting all the parts took a few weeks! Enjoy your new CDX!
