For anyone who'* interested, I'm currently adding a Delphi TNR 800 In-Dash navigation unit to my GXP. So far I've done some testing and confirmed it will retain the function of the XM Radio, Steering Wheel Controls and 12 Disc Changer. I have the Monsoon amplifier and tests so far show it can be made to work with it as well. I have apparently normal audio function (although I've only connected the left front channel so far for initial tests). I still need to confirm full function with the Head Up display and finish some final tests with OnStar (for audio only). Mounting will be tight, but I believe is very possible. These units don't have the side mounted spring clips on the side of the head unit, but there is an easy way around this. If there is interest, I'll post pics as I go.

Delphi makes these units for a variety of pick-up trucks and SUV'*. They have assured me these can't be installed into a Bonneville but I'm close to proving them wrong (GM also told me I couldn't add the factory XM either).

Definitely post pictures, you never know how comforting the support this thread could give someone doing the same thing.

Nav Unit Install Completed

Here are the project details!

Install Of:
Delphi TNR800 In-Dash Touch Screen Navigation System (Kit P/N: NA40001-11B1 / 2005 - 2008 Envoy, Trailblazer)

Installed Into:
2004 Bonneville GXP (Monsoon Audio, XM Radio, Head Up Display, 12 Disc Player, OnStar)

This unit works with the XM Radio, 12 Disc Changer, Steering wheel controls and Monsoon Amplifier.

:( Functional limitations with the Head Up Display - This unit does not broadcast to the Head Up Display. This only means that you won't see any information on your windshield (AM/FM Flags or CD Disc/Track Information). Since this is only displayed for a few seconds anyway, I don't believe it to be a problem.

:( Functional limitations with OnStar - This unit works fine with OnStar from an audio standpoint. With the actual Bonneville radio, you will see messages on the display while using OnStar (phone number as each digit is spoken, units remaining when a Units/Verify function is commanded, etc). These messages do not appear on the TNR800 display. As with the HUD limitations, not a big deal in my mind.

Certain stages of this installation were very challenging. These were all related simply to accessibility to the back of the radio bay. I have posted some pictures.

The first photo is the dash with the radio removed and the Dock-N-Lock connector pulled forward. The nav unit wasn’t intended for this car and is therefore missing the spring clips on the side which the Bonneville radios have to secure it to the dash. GM thoughtfully made the dash with the cutouts and guide posts for the standard radio mounting. The retainers which snap into the square holes are P/N 17988488 and cost $4.25/each (CDN) from my local dealer. Expensive but great to ensure the new radio is secured properly. I have marked the three square holes (red arrows) for retainers and two guide posts (yellow arrows). You’ll see them inserted in the second photo



The second photo shows a modification to the cutouts in the back of the radio bay (easy with a Dremel tool). These are necessary to accommodate the connectors on the back of the nav unit and are shown within the yellow box. They were made CAREFULLY so that the nav unit can be removed and the Dock-N-Lock connector can be put back in place (just in case I want to reinstall the factory radio). You’ll also see the snap-in retainers for the radio mounting screws.

I’ve marked with a red arrow, the wire which needs to be added for the Vehicle Speed Signal. I crimped on a terminal so I can add this to an unused location on the Dock-N-Lock ( position B-8 ). None of the Bonneville radios of this vintage use this location so it’* a safe bet regardless of which head unit is installed. These terminals are VERY hard to come by. Another option is to wire it directly into the connector that plugs into the nav unit. I chose this method so that all signals go through the custom harness adapter. I have connected the other end of this wire to the Head Up Display connector since the signal needed is present there. I tie wrapped it to the wiring harness which travels behind the bay for the instrument cluster (this will be visible in another photo).



Pictures three and four show the custom wiring harness adapter I built. It is configured to turn on the Monsoon amp and Diversity antenna module when the radio is on. Without this, there will be no audio and the antenna may not provide a good FM signal to the radio. You will notice three of the four secondary locks installed (marked with yellow arrows). There is one not shown and would snap into the position marked with the white arrow. Unfortunately, they all had to be removed since there simply isn’t enough room at the back of the radio bay to accommodate them. This isn’t too big an issue. Once the radio is installed there isn’t enough room for the connectors to wiggle out of the back of the nav unit anyway. Their other function is to be a secondary lock to ensure the wire terminals don’t pop out (there is a primary lock which should be enough). Careful handling of the wires and connectors should be adequate.

The Dock-N-Lock connector indicated with the red arrow is made by Scosche (P/N: GM07B). Two are required. I had to take terminals and wires from one, adding them to the second since they are not made to carry all the signals required in the custom harness. The wiring pigtails made for the new nav unit are sold by Metra (P/N: 71-2003-1). *** If you are looking closely, I did NOT use any standard colour coding ***. The custom harness adapter should be long enough it can be plugged in from the front, but otherwise as short as possible.





The AM/FM antenna connection required two adapters. One made by Best Kits and Harnesses (P/N: BAA7) and the other made by Metra (P/N: GM-20). It’* always preferable to have as few connections as possible in an RF circuit due to signal loss, but I wasn’t able to find an alternative. Even with the extra connections, I haven’t noticed any degradation in sound quality. I pulled the antenna coax out of the radio bay and tie wrapped the factory connector to the harness between the air bag and instrument cluster in such a way that there is no chance it will interfere with air bag deployment.



The GPS antenna mounts nicely under the dash pad. Placement is important because of the location of the ambient light sensor. I found that immediately behind the defrost vent, just to the right of the HUD unit works great. I had to flatten part of the metal mounting bracket before securing it to the dash. This is mounted in the same direction as it would be if installed in the vehicles it was made for. The coax is run down behind the dash and out through the hole for the factory antenna. The AM/FM antenna adapter coax is also routed through this same hole and into the back of the nav unit. As the nav unit is pushed back into place, it is important for the slack to be gently pulled back (from above) so it doesn’t bunch up between the nav unit and the back of the radio bay.



The nav unit is shown secured in place. I was careful to leave the screen protector in place until the entire process was complete. Placement in the bay was very difficult and frustrating because of the lack of access to the rear. If I had a swear jar, it would have been filled within minutes The two Dock-N-Lock connector halves are secured together at each end with small tie wraps to ensure they don’t separate (sorry I don’t have a picture). They are located in the space behind the radio bay cutouts and pushed up as high as possible to make room for the wires of the custom harness adapter. The tie wraps had to be applied once the connectors were pushed back through the cutouts which added to the frustration level. By far the worst part of this whole install was coaxing the custom adapter harness into the space behind the radio bay. There is simply no room for any of this wiring directly behind the nav unit within the radio bay and very little outside of the radio bay behind the connector cutouts.



With the instrument cluster trim installed, you can see that it looks great. It works great too!

WOW! Looks OEM! Great work!

Looks really good!

nice write up to!

One more important point.

There is a white plastic support pin on the back of the new nav unit which screws on. I removed this so I would not have to drill another hole in the back of the dash. I didn't want to further compromise the integrity of the rear wall of the radio bay, especially after enlarging the cutouts for the connectors. I stuck a strip of high density, self adhesive weatherstrip foam 1/4" thick x 3/4" wide x 4" long on the bottom of the radio at the back to add rear support. Without some compensatory solution, there may be the risk of stress cracks developing around the mounting holes in the front with vibration and road bumps.

That looks great! Nice job!!! Great to hear that we have, once again, overcome the GM engineers infamous saying "It can't be done"....



Congratulations Darcy!!

Very nice Darcy.....

what color does the Nav Buttons Light up?

Hey everyone,

Thanks for the compliments and support

The buttons have a white/light gray colour with the backlighting. I'm going to look into changing that to better match the rest of the instrument panel.

I'll keep you posted

damn that looks nice in there... great writeup!

can i ask how much you paid for everything?