Compass Repair or Upgrade

[Piloto]

9 hours ago, Yooper Rocketman said:

When I installed the last one, I swung it out on the ramp with it cradled in my hands.  I introduced it to the airplane interior and got NO reaction to the airframe , even when I held it up to the mount tube above the glare shield.  Installed, it seemed to work fine.  The next day I taxied it out to swing it on the compass rose and it seems to REALLY like 030 degrees; pretty much is at that setting almost at any direction now.  Maybe need to de-gaus (sic?) the plane?  Clarence....any ideas?  I hate to replace a brand new Airpath Compass.  After just adding ADS-B upgrade on a plane I'm going to lose north of $100k on when I sell it, would rather not add more cost to that misery.

Tom

Check the ground return connections. Pull out CBs to find a culprit. All the ground returns should be through the aluminum airframe but if any is connected to the tubular structure (specially at the engine mount) it will create a magnetic field on the tubing when energized 

Edited January 20, 2018 by Piloto

[Guest]

This Mooney SI may help.http://www.mooney.com/en/si/M20-95.pdf

[Yooper Rocketman]

Thanks Clarence!!

Tom