Compass warping magnet field in cab

[kcjaz]

Got a cheap Amazon car compass to put under the rear view mirror. There is definitely some magnetic field action in the cab. I know there is a speaker in the dash but I did t expect this. I also tried it in our Rav and same interference.

 

[george_tlc]

A 'good' compass can calibrate out the latent magnetic fields within a vehicle. There's lots of metal to deal with. Calibrating usually involves driving the vehicle in circles etc.

Any of those cheap/junk compasses as in your video are basically useless.

There's a reason that even with a decent hand held hiking compass you need to stand away from metal objects/vehicles etc.

cheers,
george.