new magnetic speaker interference with factory tac

[moparjohnny]

do anyone know what to use to block the magnetic interference something to put between the two? thanks

 

[Mike67]

Clamp on Ferrites will help keep spikes down, otherwise you need to use a shielded wire. You have to ground one end of the shield too.

 

[RobP]

A speaker magnet can interfere with the tach? In what way?

 

[Roscoethug]

I have the same issue. Installed speakers with beefy magnets to center dash of my '69 Roadrunner. Later installed factory tach and power off was about 2000 RPM. Closer to speaker reads 3000. A tach operates similar to an electro magnet. I'm going experiment ala Rube Goldberg and will get back with with results.