I bought an aftermarket digital compass a week ago. This thing seems to register direction inaccurately at times. It seems to act up more during daylight and works fine at night. It's ironic in how it only happens during daylight so I thought it could be due to magnetic field interferance of the compass from busy radio frequencies. Not really sure if that's the case. I calibrate the thing when it acts up and it doesn't help.
So I went back to where I bought it from and exchanged for another one and it's still the same symptom.

The toyota auto-dimming mirror w/ digital compass in my moms Highlander is always accurate no matter what time of day. What is so different between these 2 digital compasses? Could the region setting of the compass effect proper operation?

Anyhow, here are pics of the way I mounted it. Tell me anything possibly wrong with the installation. Thanks

 

I also forgot to mention that I check to see if the mirror assembly attracts magnets. It doesn't because the mirror assembly is hard plastic.

 

hmmm......is a compass really something nessesary???......i mean for so much trouble just get something else....IMO

 

Yes. I was considering the factory option but that's expensive.
Also was wonder if people here who had them had any problems with it.

 

ok guess it is in NC.....srry bud...hope it works out

 

They use a magnetic sensor to determine north. They then have a compensation for true north built in.

 

I know that the compass works off of true magnetic north.
My concern is what are the possibilities of a malfunctioning digital compass with a fresh set of batteries. Installation? Mounting area?
Possible magnetic interference from somewhere?
I guess I should have rephrase my title more clearly.
Any remedies?

 

That looks really nice. Looks OEM too.
Where did you get that? How much?

 

Thanks.
Got it at Walmart for just under $30.

 

call me stupid but what exactly does OEM stand for???.....geeez i been wanting to ask that question for a while and i finally built up the courage...lol

 

OEM = Original Equiptment Manufacter

 

Not bad of a price. Too bad you already have problems with it.
I also noticed the LED's above the compass. Nice touch.

 

 

.. aka.. stock stuff..

 

Haha, I'm not the only one who wanted a compass! I picked this one: http://www.autobarn.net/vt220.html

The biggest difference here is that the manufacturer of this compass (PNI) also designs and manufacturers the sensors and microcontrollers behind the internal compasses of most auto manufacturers. I gave it a try last week, both on its own, and in the car, attached low on the center of the windshield, and it was pretty accurate (and this unit displays to within 5 degrees). It does need to be calibrated beforehand when first put in place because it compensates for all the metal that surrounds it. The best mounting position would probably be at about the spot you have it since it would be away from the engine, headunit, etc., and the buttons would be reachable (I had to stretch out to push the light button on it when I had it on the low center, plus the suction cups would let go because of the defroster).

I had thought about an in-dash mount, but there's too much metal surrounding the sensors in that position to take a good reading. There's a reason why OEM compasses are usually on the roof (or at least the sensor is).

These compasses don't have a region setting, and they point to magnetic north. A nav system would have magnetic declination info stored which would help it find true north, assisted by the latitude and longitude info from GPS.

 

I kinda had that feeling that nothing was wrong with where I mounted my compass. In fact, that's the ideal place for one like ABRNPX mentioned. However, I just thought of the magnets that are in the sunroof motor because just behind the dome light and switches locates the sunroof motor. So that's about 6 inches from where I have my compass mounted and possibly interfering with the compass operation. I gonna try sheilding the motor tommorrow and see if that helps. I'm gonna use tin foil to suppress the magnetic field around the motor. Hope this fixes the problem.