First, did the Reatta have a compass, and if so what years?

Second, can you add one?

Third, how do you access it? I mean what catigory is it under in the TCC?

I pulled the compass box out of a Torfeno and wanted to install it in my Reatta. It seemed to have the same wire configuration as the Riv compass in the 89' FSM. I wired it in to include adding pins to the CPS. Nothing. Tomarrow I will test for voltage and trouble shoot it a bit. Just thought I would bounce it off a few mind here.

The Reatta did not have the option of a compass, but I do believe the Trofeo used a different coding system tan the Riv/Reatta plaform.

I pulled one from a Trofeo as well. The Rivi's had it as an option, I think there's pix in the owner's manual. At any rate I know you definitely can add it, just have to wire it up and activate it in diagnostics

Phil,

Thanks for making me pull my head out of my fourth point of contact. I went in, with the FSM< turned on the compass and there it was and working perfectly.

sweet to hear. It looks pretty cool in the manual

Out of curiosity, where does the unit mount and plug into the data bus in a Reatta?

Mc Reatta:

On the Reatta there was no "native" location for the compass as it was not offered as an option. It was an option on the Riviera and the Toronado/Trofeo cars with the CRT visual information system.

In those cars, it was located under the rear deck, and had a 4 wire harness: 12VDC, Ground, Serial Data x2 (data line "loops" through the module, though technically only one data line connection is required).

Anyway, you need to tap the various wires to get the connections for the compass module on the Reatta. You should probably use a switched regulated (filtered) 12VDC and ground from the central power supply rather than raw battery voltage. Then you need to find a data line to tap off of and run to the module.

There are none in the Reatta's trunk that I am aware of, so you will need to tap off somewhere near the front of the car up inside the dash. You could run a wire (or pair) all the way to the trunk if you want to locate the module there, but others have mounted it under the dash and it seems to work ok, so that is probably more work than needed.

As I side note, I find it interesting that the Toronado/Trofeo module works on the Reatta. The data stream is the same obviously, but this version of the module was made for GM by Denso. I think the earlier Riviera version was made by Delco. I guess the fact that they are interchangeable is not surprising all things considered.

KDirk

I mounted it in the trunk just as it was in the Tornado. It was a three wire conecction. One for the data line (I tapped in at the ECM). The other two are for the power. These require a 7 volt power suply. This is available from pins 16d and 7d from the Reatta CPS. All in all the install was pretty simple just three wires and entering and modifing the BCM override.

Here's a detailed write-up I did a few years ago when I installed my compass (pricing and availability have obviously changed since then):

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

Removals:

Remove the black plastic shroud over the brake and gas pedals, center filler below steering column,
the floor seatbelt trim, and all door edge carpet edging 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 and 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.

10.)Smile

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.

Roger, what model is your car? Will this write up apply to all Reattas?

With your permission I would like to add this information to my website.

How about a picture of what it looks like? Maybe I can find one out in the salvage yard. Also how about a picture of the screen showing the compass.

Great write up. I did not know any one had done it before.

It would apply to 88-89 models only.

By all means, post it wherever you like.

The compass box looks like any of the other silver electronic boxes from all over the car. It seems GM always mounted them to the underside of the rear parcel shelf within the trunk.

I think I have a pic or two I could upload I'll dig them up.

Another reason for getting the '88/'89 Reatta. Notice all the high end cars are going with the touch screen? I sat in a new Challenger last week. It had a touchscreen.

I have posted the write up on my website. It can be found here . I made a few changes for readability. If I screwed something up let me know.

Here's the Compass screen in my old '89.

How cool is that...

Ok, someone seriously needs to figure out how to make the 90-91 dash (which many prefer to the 88-89 style) work with the touchscreen. That would indeed be the best of both worlds. There would be some redundancy (A/C and radio controls), but I can't believe that it's beyond the reach of some that post here...

I think it would be easier to add aftermarket needle gauges to an '88-89, then keep the touchscreen but that doesn't give anyone with the dream of a touchscreen convertible much hope (remind me to work on that someday)

I installed one in my '88 Reatta when I first got it.
Got into program mode thru the CRT selected the code and it came up on the screen.

Two things,

1st, Daniel you are correct on the 7 volt power supply for the compass module. My haste in typing my previous post caused me to put 12V when I meant 7 . Hope nobody hooked one up to 12 volts in the meantime and smoked it.

2nd, and slightly off topic: Rawja, how did you get the "natural" finish on your dash trim? Did you just use steel wool to remove the anodizing, or something more complicated? I ask because the striation in the aluminum looks too good to be just hand rubbed. BTW, it looks sharp that way. I bet fingerprints are hard to keep off though.

KDirk

As I remember, Rawja did do it all by hand. Striking, isn't it?

Soon as it dries up I'm going compass hunting. What years, make, and model should I be looking at? Also would it be in the same basic location as the power door box?

Mainly in the trunk between the speakers. I would look in tornados (torfeno), rivs, and caddilacs, from 87'-91'. I would also call or visit a junk yard that has an interchange and check if they have a interchange for the 89' riv compass.

Continuing the minor hijack of the thread, click below for instructions on stripping the anodizing from the dash:

HERE

Rawja,

Thanks for that info, good to have for possible future use, as in whenever I manage to buy an 89 (some ways off yet I think).

Back to the compass for a minute, I have another twist here:

I have in my possession a Denso manufactured GM compass module from a Toro/Trofeo marked with part number 03521846. Also has the ID number 068000-7060. Not sure what this number is, perhaps a Denso number or a version number/firmware ID.

But the interesting part is this: it is marked 12V (12 volts)! Note also that this module is in a black plastic enclosure, not the metal box like the one under discussion in this thread.

Now, I think this is from a 91/92 Toro, and here's why. The CPS (central power supply) was eliminated in the E-platform cars in 91, so there was no more filtered 7 volt supply available, everything went to 12 volts only.

The big question is, will it work in the pre-88/89 Reatta as long as it is hooked to a 12 volt supply? I would think so, since it is still broadcasting the same serial data. This is supported by the fact the the rest of the Toronado/Trofeo VIC touchscreen system remained largely identical from 89-92, just some minor changes for the addition of SIR in 1990, and the omission of the CPS in 1991.

Anyone have the inclination to test this theory? If you can find this compass module from a 91/92 Toro, and swap it in place of the older metal version, just changing the supply voltage, then we could find out if this is another source for the part.

If nothing else, I may be willing to lend this module I have to someone to try it. It would be good to know if this is usable on a Reatta.

KDirk