Upgrade old CD nav system to newer DVD sys on 01 STS

[mixbox]

Is this possible? How much rewireing is needed?

Thanks in advance

[Bruce Nunnally]

Anything's possible, but it is unlikely to be simple. Between your Cadillac and 2001 there were likely to have been changes to the way that the entertainment/navigation system interfaces with the communication bus on the vehicle. This means that even if you get all of the bits and pieces to the nav system from a 2001 and hook them up to your car it may not work.

That is how you would TEST to see if it will work though -- look on ebay or similar for a system that has been removed from a wrecked Cadillac. Unplug the old one, plug in the new one, an see what happens. Take lots of photos, and let us know how it goes as you proceed.

Your year model of STS did not come through for some reason; you can change it here

[mberlant]

I just got through doing the very same thing with with my 2001 DTS that I moved to Japan. Much of what I did you will need to do to your STS.

My 2001 DTS came with factory Nav, which means that parts of the system are in the dash and other parts are in the trunk and the glove box. I believe that your STS has the same system, judging by photos of the control head installed in the dash. Unfortunately, there is no way I know of to fit a newer GM system into an older GM car, so you will need to buy an aftermarket system from your favorite supplier.

I purchased a Panasonic system and have just now got it working. You will need some interface parts and plastic parts to make it work. Assuming that you have the BOSE amplifier system you will need a PAC-Audio OS2-GM32 radio interface module to mate the radio with the car and the BOSE amplifier, a PAC-Audio SWI-?? steering wheel button interface module (?? varies based upon the stereo you buy. I used the SWI-X to turn my button presses into the iR commands Panasonic requires.) and a Metra 99-2005 mounting bracket kit. The mounting bracket is only available in 1-DIN size, so you will have to choose your system accordingly.

There are four components of the old system to be removed - the control head from the dash, the CD changer from the glove box, and the radio and nav/CD unit from the trunk. Save the bracket from the CD changer to reuse with the "2nd half" of the 1-DIN/1-DIN system you end up with.

You will need to experiment with mounting the new display head in the Metra bracket. My DTS has a very shallow cavity, so I had to fabricate a sleeve to allow the radio to be mounted with about 35mm of the nose protruding from the front of the bracket. Your STS might be deeper; I just don't know. You will also need to adapt the part that goes in the glove box, because you want to use the 185mm wide bracket with your 150mm wide nav module.

Electrically, you will need to make most of your connections in the trunk. You will find that the OS2-GM32 module does not mate with the connector behind the dash; only with the connector in the trunk that you removed from the radio module. Likewise, the car's AM/FM antenna is in the trunk. These wires need to be extended from the trunk to the dash. Cut the 16 pin cable (the side that mates with the car) and extend all of these wires except the double-purple wire to the front of the car. This will allow you to locate the OS2-GM32 module behind the dash. The double-purple wire needs to be connected to the control head connector. Find the two purple wires in the 5th position and connect to them. The purple wires are the Class II digital interface, and will cause noise in the speakers if you extend this wire in the same cable from the trunk. Another wire that may not travel in the same bundle as this cable is your VSS (Vehicle Speed Sense) wire. Route this wire separately from your new nav system to the trunk and connect it to the Green/white stripe wire in the connector that used to connect to your old nav/CD module. This wire will keep your vehicle "moving forward" when you enter a tunnel or covered car park.

While you are inside the trunk you should see the two GPS antennae (one for OnStar and one for Nav) on the underside of the rear shelf, next to the rear speakers. Your new GPS antenna should be mounted here. I added a small bracket to the mounting plate for the right-side GPS antenna and stuck my new magnetic antenna to the upper side of that plate. You may choose to turn one of the existing GPS mounting plates upside down and put your new GPS antenna on the other side of that plate. The entire rear shelf is transparent to the GPS, so you should be able to put the antenna wherever you wish. Mine is about 8cm to the right of the old right-side antenna, and works great.

I estimate it took me about 8 hours of unhurried labor to perform this installation, including twice modifying the wiring to remove the interference (the VSS and the Class II digital interface).

Good luck with your project.