Hawkjet posted this a long time ago as part of another project he worked on. Some good info and pics here.

https://www.gmforum.com/t263324/

Sorry, haven't had time to do a write-up yet of just the stereo removal.

No, thats all I have.

Sounds like your volunteering Darcy, I'll send you the PDF and let you have at it. LOL

My intension from the time I bought the car was to hook up a factory XM radio, I know you can add a satalite unit that you can mount any where but they don't work as well as the factory units and I hate extra crap laying around in my car. My car already has the roof mounted fin antenna and I thought that was the XM antenna, I was wrong ? Any way I talked to several people about putting in a factory XM and they all said you can not do it because its connected through the computer which I thought was crap. And now I have seen that you have done it which is Frickin Awsome ! ! ! Can you give me some advice on doing this and were you able to change the lights in the Caddy radio to match the red in the Bonny ? By the way that was a GREAT link to removing the dash. Thanks

Well, GM told me I couldn't add the factory XM radio either. I didn't much care for their answer so I just went ahead and did it anyway

The antenna on the roof, depending on model, is a 3-in-1 device. Mine has three coax connections coming from the base. One is for OnStar GPS (so they can located your car in crashes and theft situations), one is for OnStar voice communication and the third is for the XM DRR (Digital Radio Receiver). You would need to see if yours has this third connection or not. It would be a tan/gold colour connector and not currently connected to anything if it does.

There are many "computers" in the Bonneville and it doesn't connect "into" one as such. Instead, it connects to the data bus that all the computers (class 2 data modules) connect to. This is because the XM receiver mounts in the trunk and the radio head unit needs a way to control it. Signals are sent over the data bus to give the XM receiver instructions about changing stations and when to turn on and off the audio etc.

I built a custom harness to install mine. This allowed me to connect into the rear fuse block and tie into the audio connections and the data bus.

Do you have the trunk mounted 12 disc changer?

As for the navigation radio, yes I did change the backlighting. This thread shows the installation of my original navigation radio. I've since put the Bose Luxury version in, but the process is similar. Changing the backlightinig is identical.

In Dash Navigation Unit.

Another related thread (still not the Bose Luxury edition though)...

Navigation - Update.

WOW ! ! ! Fantastic reading . . . My GXP does not have the CD changer, And as far as he roof antenna. I would have to remove the head liner to check that out ? whats involved with that ? Where is the rear fuse block located ? I really just wanted a stock XM head unit. I want the OEM look. But WOW that Caddy head unit that display'* Pontiac is fantastic !! So let me line things up... 1) I will need a Head unit 2)a wiring harness to go from the head unit to the trunk mounted XM unit. and probably a new antenna. The good news is I don't have a HUD to deal with. what was the part number for the Bose head unit you installed. That is sweet. And do you have a part # for the XM trunk mount unit ? I have been wrenching on cars for 25 years but this looks a bit challenging. Nothing ventured nothing gained. Many Thanks, Tim

The reason I asked about the 12 Disc Changer is because the XM receiver and the CDX share the same audio input on the back of the head unit. Whether you have or don't have the CDX only changes how you would have to connect the audio output from the XM receiver.

The head unit doesn't change. Your'* already supports XM. GM doesn't have head units with or without XM, it is always a seperate module installed in the vehicle. In this case, GM put the Bonneville XM receiver in the trunk. As long as you have a 'BAND' button (which you will) instead of "AM/FM", the head unit will already have the software to control the external XM receiver.

To check whether you have the correct antenna, you don't need to completely remove the headliner. If you remove the 'C' pillar trim on both sides and carefully pull the weather strip down from around the top of the rear doors you should be able to gently lower the rear part of the headliner to have a look. Be very careful doing this or you may kink and crease the headliner. Look for the three cables coming from the antenna. The two for OnStar should be blue and purple IIRC. As mentioned, the XM cable is a tan/gold colour.

At a minimum, you will need the coax cable that runs from the roof mount antenna down to behind the trim inside the left side of the trunk. The cable is P/N 89047299. You will require the mounting bracket for the XM Receiver, P/N 25732544. The XM Receiver itself is P/N 15125061. There is one listed on eBay right now:

eBay Motors: Factory Chevy/GM OEM XM Satellite Tuner Delphi/Delco (item 110357033165 end time Mar-05-09 11:58:20 PST)

The rear fuse block is located under the rear seat cushion. As for the wiring harness, I can build one but it'll probably be a few bucks because of what'* involved. Not super difficult, just time consuming to do a good job. I built one for 1993 SLE that accomodated both the XM receiver and 12 Disc Changer. I only use factory connectors and don't splice on pigtails, new terminals and wire all the way.

In this case, the HUD would not be a problem because you don't need to remove the upper dash pad.

Missed this in the last post...

The navigation head unit I used in the threads you saw was P/N 15800000. This was the Bose (Non-Luxury) version. The new one I installed is the first revision of the Luxury version, P/N 10377531. I'm still doing some investigation because the one I really want is P/N 15800001. There'* more background information to this story which I won't get into just yet. In any event, to install the Bose Luxury version you also need to change the audio amplifier and make some wiring changes in the trunk. I'm not sure I would recommend this just yet until after I finish my testing.

Here is a photo of the custom XM/12 Disc Changer harness.



This is a photo of the XM Receiver installed in the vehicle.



These are photos of the roof. You can see the three cables coming from the antenna. Colours as indicated in previous posts.

I should mention that once everything is installed you might require a trip to your GM dealer. There is a set-up procedure for the XM receiver module that may need to be done using a Tech 2 scan tool. This can only be done with the actual GM software. Aftermarket scan tools (Snap-On) etc. used at many non-GM repair facilities can't perform this procedure.

If everything is installed and configured correctly, you will be able to press the 'BAND' button on your radio and cycle through AM, FM1, FM2, XM1 and XM2. If not, you won't see the two XM options.