I did more research today and found the following instructions on another forum:
First, a little history about adding the CDX in vehicles not factory equipped with this option...
In the early production years of the 2K+ Bonneville GM offered an “Installation Kit” for the optional CDX. The kit included a wiring harness, bracket, additional mounting hardware for the bracket and the trim panel. This, along with the purchase of a CDX and magazine, and anyone who didn’t have the factory installed CDX was able to add it to their 2000-01 Bonneville. The only reason this kit didn’t work for 2002+ was because of the terminals crimped on to the audio cable. In 2000-01 the wires plug into a connector under the dash pad, not the DNL connector at the back of the radio. By modifying the cable to use DNL terminals and not GT 150 series terminals, this kit could be made to work for 2002 and newer. Unfortunately, this kit hasn’t been available now for at least a couple of years. A few of us checked and there is no left over stock at any dealership in Canada or the US.
Here are a few important abbreviations and general information items you’ll need to know to understand this article.
DNL – Dock-N-Lock
RCDLR – Remote Control Door Lock Receiver
TPA – Terminal Position Assurance (Lock)
BLK – Black
BLU – Blue
BRN – BRN
DK GRN – Dark Green
GRY – Gray
ORN – Orange
PPL – Purple
WHT – White
Wires will be either a solid colour alone, or a solid colour with a stripe. For example:
ORN – This indicates an Orange wire.
BLK/WHT – This indicates a black wire with a white stripe.
In most cases, Delphi connectors will have cavity references embossed into the plastic housing. A few connectors have every cavity identified while some connectors have only the end cavities identified. This still permits anyone looking to make determinations about what each cavity is.
Here is information about the BLK 10 cavity CDX connector.
1. - BRN/WHT (Left Audio Signal)
2. - DK GRN/WHT (Right Audio Signal)
3. - BLK/WHT (Audio Common) **
4. - BARE (Drain wire for shielding purposes)
5. - ORN (Battery Positive Voltage)
6. - Not Used
7. - BLK/WHT (Ground ) **
8. - Not Used
9. - PPL (Class 2 Serial Data)
10. - PPL (Class 2 Serial Data)
** There are two BLK/WHT wires. Care should be exercised to ensure you connect the correct one in each instance.
Here is information about the GRY 32 cavity DNL connector:
A9 – BLK/WHT (Audio Common)
A10 – BRN/WHT (Left Audio Signal)
A11 – DK GRN/WHT (Right Audio Signal)
Here is information about the BLU 4 cavity RCDLR connector:
1. - ORN (Battery Positive Voltage)
2. - PPL (Class 2 Serial Data)
3. - PPL (Class 2 Serial Data)
4. - BLK/WHT (Ground)
Now, on to the connections...
BEFORE YOU DO ANY 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(*) 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.
Using a 3 conductor, shielded audio cable (assuming colours are black, white and red) with a drain wire, make the following connections:
Step 1: Connect the BRN/WHT wire of the CDX pigtail to the WHT wire of the audio cable.
Step 2: Connect the DK GRN/WHT wire of the CDX pigtail to the RED wire of the audio cable.
Step 3: Connect the BLK/WHT wire of the CDX pigtail (Pin 3 on the CDX connector) to the BLK wire of the audio cable.
Step 4: Connect the BARE wire from the CDX Pigtail to the BARE wire of the audio cable.
Step 5: Splice the three donor terminals with wires onto the three conductors of your new audio cable. You likely won’t have matching colours so don’t worry too much about that. Just be sure you ultimately keep track of which wire is left, right and common audio.
Step 6: Remove the trim around the instrument cluster, radio and climate control. You will need to remove two plastic rivets above the instrument cluster first. Look at this thread to see how these retainers work.
Step 7: Remove the radio from the dash. Press each of the four spring clips toward the middle of the radio and pull towards you. There are no connectors on the back that need to be unplugged.
Step 8: Remove the DNL connector from the back of the radio bay. Slide it up and pull it towards you.
Step 9: Remove the plastic cover from the back of the DNL connector. It should either be WHT or GRY. You must also remove the TPA lock from the bottom (row ‘A’) of the connector. This will be BLU in colour. This must be done in order to install the new terminals.
Step 10: Route the audio cable from the CDX mounting location to the dash and through the back of the radio bay to allow for the wiring to be added to the connector.
Step 11: Insert the terminal spliced to the BLK audio cable wire into A9 of the DNL connector.
Step 12: Insert the terminal spliced to the WHT audio cable wire into A10 of the DNL connector.
Step 13: Insert the terminal spliced to the RED audio cable wire into A11 of the DNL connector.
Step 14: Reinstall the TPA lock.
Step 15: Reinstall the DNL connector to its original position in the back of the radio bay.
Step 16: Reinstall the radio. I would recommend testing everything before reinstalling the trim.
Connecting Power, Ground and Class 2 Serial Data Lines...
The way I’ll outline in this article is similar to the method GM used in the Installation Kit that used to be available. To do this you’ll need to splice into four wires of the vehicle.
First you need to locate the RCDLR. This is a small tan module clipped into the metal frame behind the rear seat accessible from the trunk. It will be located on the left side, near the 6x9 speaker mounted to the rear shelf. You will need to remove the black plastic trim panel that goes across the width of the trunk immediately behind the rear seat back. Once you have the trim removed, look for the module. It’* easily identified because it will have a single BLU connector plugged into it. The connector will have four wires; 1 ORN, 2 PPL and 1 BLK.
Step 17: Unplug the 4 cavity BLU connector from the RCDLR and remove 2-3 inches of the black harness wrap tape.
Step 18: Extend the ORN wire from the CDX pigtail, across the trunk and splice it to the ORN wire going into the BLU connector. This will be your Battery Positive supply. You do not need to add a fuse in this line. The CDX will be protected by the same circuit as the RCDLR. This is how GM accomplished this with their “Installation Kit”. In the factory installation (along with the harnesses that I build), there is a fuse specifically located in the rear fuse block for the CDX.
Step 19: Cut ONE of the PPL wires going into the BLU connector. Leave enough wire coming out of the connector that you can splice a wire onto it. You will now have two PPL wire ends near the BLU RCDLR connector.
Step 20: Extend the two PPL wires from the CDX pigtail to the BLU RCDLR connector. Splice each of these wires onto the two wires you have (from cutting the one PPL wire). It does not make any difference which of the two wires gets spliced to the wire going into the connector or the wire going into the vehicle wiring harness. In essence, you are simply adding the CDX in SERIES with the other Class 2 Data devices.
Finally, connecting the ground wire...
Step 21: There are a couple of ways you can make this final connection. You have the option to extend the final BLK/WHT wire from the CDX pigtail (make sure you have the correct one of the two) to the RCDLR connector. You can splice it to the BLK/WHT wire there.
The other possibility is to locate the ground splice pack. This is a small black “Module” that is bolted to the body, inside the trunk, just in front of the right rear tail light. You will note that it has several BLK or BLK/WHT wires connecting into the bottom. These are all ground wires and you can splice to any one of them.
Step 22: Plug the BLU connector back into the RCDLR module.
Step 23: Reconnect your battery.
Step 24: Load your CDX magazine. If it came loaded in the CDX, slide the door all the way towards the front of the car until you hear a distinct snap. You should see a white light illuminated at the bottom and front of the CDX opening. The magazine should eject on its own. Follow the directions in your Owner’* Manual on how to load the CD’*.
Step 25: Load the magazine into the CDX. Again, this is straight forward but instruction can be found in your Owner’* Manual if necessary. Close the CDX door all the way, again listen and feel for the snap as you slide the door rearward.
Step 26: Turn on your ignition to the ACC position. Turn on your radio. You should see a small CD STACK flashing on the display and hear noises from the CDX. This is the mechanism checking all the discs and determining how many tracks are on each. Once this process is complete, the CD STACK will illuminate solid on the radio display. Follow the instructions in the Owner’* Manual on how to use this CDX option.
Step 27: Once everything is verified as working, reinstall the dash trim along with all the trim in the trunk.
Step 28: ENJOY!!
So it seems that it can be done but it will be a pita.