[May 31, 2015]

With my Outside Air Temperature (OAT) sensor at home, I decided to run a few tests with it. At room temperature, it read 9.82 kOhm of resistance.

In Ice water, 29.06 kOhm

And in near-boiling water, 2.456 kOhm. Seems to be working fine?

Back to the hangar, I looked through the GRT menu of where it retrieved the OAT data - I couldn't remember if I wired it through the EIS or the EFIS. The EFIS has the option of getting the OAT automatically, through the EIS, or through the local AHRS.

Hmmm, after disconnecting it from the EFIS, it read 314.8 Ohm.....this is slightly off from my previous readings?

And moments later 7.13 KOhm?

Looking at the EFIS - negative 96 degrees F (The winter never seems to end!!!)

And the next moment, 90 degrees F? I seems clear there is obviously an issue with the sensor. After I disconnected it from the EFIS, the resistance would grow quickly from 200 Ohms to 7,000 Ohms.

I thought for a hot second there could be an easy fix with some bad solder joints in the sensor, but after pealing back the heat-shrink tubing, it looks relatively unserviceable. At least I found the issue. New OAT sensor it is!



Last Modified: June 24, 2024