Cannot get rearview mirror compass to calibrate.

[crtfour]

Hi,

I recently added to my truck one of those rearview mirrors that tells you the direction and temperature. It is new. It displays a direction like it should, but usually the wrong direction. Also, it constantly displays the message that it needs to be calibrated. From past experience, these things either calibrate on their own with normal driving or by driving in circles. The owner's manual suggests only these two things, and I've tried both with no luck. Does anyone else know of any tricks or ways to get it to work right? Thanks a lot.

Rob

[ibthumpin]

thats the only way I know of to do it. It self-calibrates, I dont think its even anything you have to invoke (by pushing button).

[BarbWire]

http://www.diynet.com/diy/ab_parts_accessories/article/0,2021,DIY_13690_2271284,00.html

from reading that article several things can possibly cause the problem.
bad ground
too close to an electrical interference source at the probe end of the compass/temp wire or run thru a high interference area.
improper installation of the wiring into the vehicle.

there are only two styles of compasses i know of magnetic and gyroscopic. from the way these things sound they are not gyroscopic. if it is magnetic then installing it close to steel parts can affect the compass adversly as can electrical motors.

those would be my guesses i cant find anything on exactly how the auto compasses work but i would bet its magnetic and they have to also be oriented with the vehicle facing correctly.

http://www.mitocorp.com/files/Gentex_Mirror_by_MITO_Corporation.mht

this might also help it may not be your exact model mirror but the manufacturer should have similar instructions.

[ibthumpin]

good suggestions but the compass unit is built right into the mirror housing - there is no sensor or signal wires for the compass. And you really have no choice of where to mount it beings that the compass is conatined in the mirror..... at least if he's got a factory mirror.

crtfour - what mirror do you have? you dont live under power lines do you?..... as funny as that question seems if there are any high voltage tranmission lines in the area it could throw off the compass.

[BarbWire]

the article also says that particular compass needs to be driven in a circle 3 times each circle taking at least 45 seconds to complete to calibrate it. so if he is driving in circels too fast it might not calibrate. things like this are generally fairly generic since there is usually only one way to do certain things and often devices like this that are made by different companies pay the patent holder for the right to manufacture said device. so it would reason that the same general rules of automatic calibration aply to all mirror compass devices.

basically try driving in slower circles...

[OKLAGMCRUISER]

I accidentally installed the wired module, that is below the mirror , backwards and had an incorrect reading until I turned it around. Otherwise, drive slowly in circles in a parking lot...it will eventually calibrate itself...or your mirror is bad.

[angelo]

I just installed a mirror, ann I had to change the zone I was in to make it read the right direction. Turn on the compass and hold the button for 8 seconds and the zone number would show. then select the zone you are in. The info is in your owners manual. after selecting the zone leet go of the button and it will go back to the normal mode. then calibrate it.