Overhead console compass question

I searched and didn't find anything on this so I'm pretty sure this hasn't been asked before...

My wife's Blazer has the compass in the overhead console and like many other little features you don't think about till you have them it's become very convenient. What I want to do though is install a compass like this in my BMW. Every aftermarket unit I've seen is either a butt-ugly ball-compass or a way too big digital one with all kinds of extra features. If I can't find a simple straightforward LED compass that's small enough to put in an equivalent location like the Blazer's overhead console I want to see if I can retrofit one from a junkyard Blazer into my car. So on to the real question: Is the compass more or less a stand-alone unit that I can just plug into power and have it work or is there more to it than that?

there is all different consoles on e-bay. i just installed one in my son's blazer, but i don't know about a bmw. first you would have to get a wiring dia for the bmw and try to cross match it to the chevy. looks to me like that's possible with some home work, or go to a graveyard and pull one from a doner beemer..you have to tap into the vss signal from the ecm to make the compass read correctly, thats where you need the diagram for the bmw.

If all you want is a compass check Wal-mart. I've seen little digital compasses there, they had several different ones. I'm not talking about the ones for boats or hikers, they are made for vehicles. I think I saw a small one that mounts on the rear view mirror, too.


You can also buy radar detectors that have them built-in.... I've got one.

An easier thing to do is check out some of the aftermarket rearview mirrors; I've seen some with both a built in digital compass and auto dimming.

Like I said, I've seen them around, but really don't know where you would go to find one. I'd start with eBay or even JCWhitney.

I am in the middle of putting a console in my Blazer, and apparently the compass part doesn't work unless the VSS (vehicle speed sensor) is wired up. Don't know how you would do this crossing a GM console / compass to a BMW.

I've checked on the aftermarket mirrors that have it built it but they're either around $300, have a huge frame aournd them, or both. Interestingly enough some of the aftermarket ones I found appear to be identical to the auto-dimming mirror my wife's Blazer has. It makes sense that GM would buy somebody else's product but I figured they'd dress it up a bit different at least.

It's more than a little odd that the compass part won't work without a VSS signal. I guess I'll just keep an eye out for a small enough one at Wal-Mart or something that I can mod into my existing overhead console...

Dudes;

Ever think for a second that one can just build a clock circuit to "Fool" a console into thinking it has a VSS signal? A 555 timer IC in this case is your friend...

Does anyone know why it needs a VSS signal? The compass in my radar detector works just fine without one.

Yeah, the VSS pulse signals the console that the vehicle is in motion. It varies the update frequency of the readout based on the speed of the vehicle. Of note, it will greatly vary how soon it updates the external temperature sensor readings, but any pulse will make the compass immediately update.

Yeah, the VSS pulse signals the console that the vehicle is in motion. It varies the update frequency of the readout based on the speed of the vehicle. Of note, it will greatly vary how soon it updates the external temperature sensor readings, but any pulse will make the compass immediately update.
Thanks. :thumbsup:

Found this while surfing, it's a cheap and easy way to add a compass:
http://heartlandamerica.com/Item/default.asp?SKU=91502&Cat=1143&Prod=57971+88309+40243+91502+70532+61261+93594+947 47

Thanks, but the one thing I'm avoiding is anything looking tacked on. I have an unused area of about 1-1/2" square on my overhead console next to the check panel. What I want to do is integrate a digital compass readout into that area, preferably in amber/red to match the rest of my interior illumination.