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Want to buy used Compass


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The compass is definately neat, and moderately beneficial. A few of us here have installed them. It gives you a screen the shows a car sitting at an intersection with forced perspective and mountains on the horizon. The direction the car is heading in is written large across the sky and the compass points that are at right angles to the direction the car is facing is shown an two street signs posted at the intersection.

The compass was an option on the Riviera and as such, the Reatta's systems are equipped to accept its installation.

Detailed installation instructions follow:

I ordered the compass module from GMPartsDirect for like $135.00, part # 1647056.


Remove the black plastic shroud over the brake and gas pedals, center filler below steering column,

the floor seatbelt trim, and all doorway edge carpet moulding at the drivers door. I also pulled up the carpeting along that edge, exposing a black plastic raceway which is used for the factory wiring.

While you are under the steering column, drop the central power supply box from it's mount located over the gas pedal, which will bring down the wiring and connector for easier access.

Compass Pinning Info

1 Data Line

2 Data Line

3 7 Volt Power In

4 7 Volt Isolated Ground

I used #14 THHN stranded wire for the installation, as I had it on hand in multiple colors and the stiffness and quality of the wire makes it easier and neater to work with. I taped the bundle together like once every foot with electrical tape.

Was unable to locate the proper connector, so I made individual crimp sleeves to attach each of the four wires to the appropriate connection pins on the compass, compass was mounted on the under the rear window shelf on the drivers' side using industrial heavy duty velcro like the stuff they use for EZ-Pass toll transponders. Wires were easily fished thru from the trunk, without removing any of the rear shelf trim using a drycleaning hanger as a snake. Raceway under the drivers' door opening is hinged to allow you to lay the new wiring in. I snaked the wires up thru the kickpanel raceway and to the area below the steering column where the wiring splits off from each other. The 2 data lines were routed to the ALDC connector located just above the emergency brake, connection easily made by removing the connector and using inline taps to the the data wires fron behind the connector. The data lines are tan and are the top left 2 wires going into the rear of the connector (it doesn't appear to matter which wire goes to which in the data loop). Power lines were routed up and over the steering column and to the hanging power supply. I unhooked the power supply connector (everything in the car goes dead when you do this). Looking at the power supply connector, there is a blue and a beige termination stay within the connector, you want the beige set, which is numbered. power to the unit goes into #16 and the isolated ground goes into #7. push the beige wire retainer back into the connector and reattach to the power supply.

Computer Programming Instructions (thanks to Sahein):

1.)Get into diagnostic mode by pushing the climate control warm and off buttons simultainously.

2.)Select BCM then BCM override.

3.)Select BS07.

4.)Remember this displayed number so you can return the BCM programming to normal.

5.)Push override up arrow until code 252 is displayed.

6.)To permantly store the new option code: Press and simultaniously hold for more than 3 seconds the GAUGES and OPTIONS buttons surrounding the display.

7.)Turn the key off and then back on.

8.)Select the OPTIONS button surrounding the display.

9.)Compass should appear in the menu. All of the old options are still there but located under a different level.


Once the options code has been changed, the compass screen comes up whether there is a compass attached to the car or not, so before you close everything up, go thru the calibration setup on the compass screen (this will involve driving the car in a circle), don't worry about directional accuracy for the moment, just make sure it changes direction when the car does. If the car asks you to point the car north after the circle, congratulations, it is working! Hit return to see you compass in action. if the directions change with the orientation of the car you are good to go. Close up all that you have disassembled. Afterwards I recalibrated the compass with a hand held compass to ensure accuracy.

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Wow! That was a lot of work....Sincere Thanks!!

Instructions are going to be copied as soon as I close.

Happy Holidays!


After copying and reading again I realized that a touch screen must be present/utilized (I have a 90). Will still retain, 'cause you never know.....thanks again!

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Merry Christmas and Happy New Year to all...

As for the compass, if you have a '90-91... Forget the compass module. We don't have the computer monitor to view it.

Alternatively... You can get a rear view mirror with a compass in it from a 2000 or newer Suburban, Tahoe, or Avalanche that's been wrecked, possibly. I've been looking for one for a while, though. Junk yards pull the electronic mirrors before you can get them, won't sell them, and tend to look at you funny when you ask where'd they go. You may also want to check out the new Passport and Whistler series radar detectors with the compass in them. They're about couple a hundred $$, but compared to the price/value of a new GM rear view mirror w/ compass ($499-799 + taxes, no joke mad.gif !!!), at least there's some worth to it if you can have a detector in your state. Also JC Whitney ( http://www.jcwhitney.com/product.jhtml?CATID=53735&BQ=jcw2 ) and Hemmings tends to have a few somewhat decent units with mileage computers and compass now and then; again, usually about a hundred or two.

Sorry to be the bearer of the bad news.

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Can anyone tell me where I can find or what the Compass module looks like in a 89 Riviera and where would I find the options menu after the compass module is installed in an 89 Reatta? smile.gif

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On the Riviera, the compass module is mounted under the parcel shelf on the drivers side within the trunk. It has an aluminium case and is roughly the size of a Palm Pilot, only thicker.

Once the Reatta's programming has been changed, the compass readout can be accessed under normal conditions by pressing the "options" hard key, followed by the "compass" soft key that is on the resulting menu.

Even without the compass installed, you can change the options value using the programming instructions posted above to see what the compass display looks like.

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