Outside Air Temperature

[GAdams]

My 337D OAT gauge consistently reports the temperature lower than it actually is. Can anyone point me towards a previous thread that deals with this subject? Or can anyone tell me where to start to troubleshoot the problem? The Probe or the Gauge?

[Learjetter]

Relevant pages from non-current G and H model service manual attached. Perhaps they’ll be of some help in determining what the problem is?

—edit: added OAT mechanical gauge page to attachment

[JimC]

The D uses just a basic stick thermometer, right? No electronics?

[GAdams]

Yes just a stick. No electronics. Old school.

[JimC]

I'm not sure that the probe & gauge are separable. There's a bimetallic spring inside. If someone were to remove the cover and overload the spring in one direction, the temperature indicator would probably consistently show several degrees higher in the direction of the overload.

[GAdams]

The documents Learjetter sent me of the maintenance manual appear to be the same system I have. The probe and the gauge are not one in the same. I wish it was.