Read posts about mirror that also has compass. Very expensive.

I got a car compass for Christmas. It has calibration screws.

Now wondering what to do to make compass read correctly. Readings accurate in driveway. Inside car compass goes 180 degrees awry: reads west when should say east and so forth. Mechanic friend--who is also a pilot--stopped by to help. He said RX8 has a strong magnetic field in alarm system or somewhere to make compass go nuts.

Suggestions please?? Thanks for your help!
Hes

 

where are you mounting the compass. if its on the center of the dash, most likely it is due to the center channel speaker if so equipped.

 

To prove that your mechanic friend is correct, wrap the compass in foil or screen leaving enough of the display open so that you can check it's operation. If it operates normally, it is likely your friend is correct. Try another compass to see if it is also affected.

 

Foil isn't going to work. Aluminum is a non-ferous metal and wouldn't affect magnetism(so much for tin hats). If it works in the driveway and not in the car, there is obviously something in that position that is affecting it. There isn't anything you can do to correct it, other than trying a new mounting location. I ran into this problem on my boat. And there a compass is a necessity.

 

Magnetic compass is not very useful for urban settings too. I ripped out the magnetic compass from my previous car because it would go crazy in different locales.

For me, an accurate compass is guided by satellites, not magnetic fields.

 

computer doing strange things--getting bounced with error reports to Microsoft. Sorry if list somehow gets more than one of my answers to your post.

Got lost in very bad part of town a while back; no street signs, street lights few and far between. Was between 11 and 12 pm and a frightening experience. After 20 minutes trying to get out was thoroughly confused as to my location. No one, including the police, can help via cell phone if they don't know where I am.

Read your messages. Then tried two compasses. Both OK in driveway but haywire inside my 8. Several different readings when held here and there to windshield. Centered on dash appears "least" inaccurate. Now wishing I'd bought an 8 with navigation system.

Would one of those spendy mirrors with indwelling compass be any better than this stick to the dash thing?? Does Mazda make such a mirror?

Now thinking that even though compass inaccurate, a constant of some kind would still be helpful. I don't know what else to do.

Thanks for your guidance.
H

 

I recently received an auto-dimming mirror with built-in compass (see DIY "auto-dimming mirror" thread). I find the compass to be reasonably accurate within its resolution. It reports the 8 compass points (N, NE, E, SE, S... etc) . It is digital and the unit self-calibrates after you have driven 3 complete circles and entered a "correction code" for you geographical region.

The two things that will throw a compass are proximity to ferrous metal, and proximity to wires through which electricity is flowing (creates magnetic field). As your pilot friend suggested, electrical wiring can strongly affect a compass.

I don't know if the relative success of my mirror's compass is due to its electronics providing smarter calibration or because of its mounting location. But if you can't find a reasonable mounting location where your standalone compass is accurate, the mirror may be worth a try. I was mostly interested in the auto-dimming feature, but the "homelink" buttons and compass are nice features also.

Or, you could opt for a better compass instead of buying the whole mirror. Search someplace like Amazon for "digital car compass".

I am assuming you tried to "dial out" the error with the calibration screws, but were unsuccessful?

 

Ehh if you get lost easily a compass isn't going to help you, seriously. A compass and a map? Yeah maybe but you still need to have a good feel for navigation. If you don't have a good feel for direction I would just avoid that part of town, or any part of town that doesn't have street signs.

I would get a Tom Tom. Though that part of town may not be described in detail in the Tom Tom it would be able to point you in the general direction of where you need to go, or from where you came.