Picture requested for under wing OAT probe location

[Stephen]

Installed JPI EDM 900 in my 1969 F model. The JPI supplied OAT probe is using the old,  through-windshield mounting location,  but is reading crazy numbers (i.e. starts +/- 1 degree of field temp and on switching on master slowly climbs into ridiculously high levels ...like field temp + 60-80 degrees). This behavior is both pre and post-engine start. In flight yesterday it read 154 deg F at 4500'. JPI support says this has to be pinout/grounding/interference based and cannot be a probe malfunction. My installers have checked pinout grounding and say they did it right... interference is a "go fish" issue. So, my solution is to order a new temp probe and cable and re-install it to the (preferable) under-wing location, which changes out most of the variables in the equation. I have been hitting google and MS and am finding discussions, but no pictures of an under-wing OAT location.

 

ASK:  Could I get a pic of anyone who has an OEM underwing installation. : )

 

Thanks,

 

Stephen

[Guitarmaster]

Here ya go.

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[201er]

Mine is mounted in the pilot side leg vent indent. Not sure if an F has the same scoop.

[Stephen]

No problem thanks; I think I am following the location as described. 

[KSMooniac]

The factory location in my '78 J is on the bottom of the copilot side wing on the middle of the inboard most "small" oval inspection panel.  Just outboard of the main gear and fuel tank. Sorry, I don't have a picture. 

This is the correct location.

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[Stephen]

13 minutes ago, KSMooniac said:

This is the correct location.

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So as pictured by guitarmaster above except actually mounted in the oval panel itself correct?

[KSMooniac]

Definitely mounted in the inspection panel. I think the panel is further act in the wing, though. I don't have my maintenance manual handy at work with a location in a pic. I don't think it is critical as long as it is on the bottom of the wing and out of direct sunlight, away from exhaust, etc. Outboard of the gear is the J factory location, and I have one under each wing.

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[DVA]

It's a Bravo, but this is where the probe is located.

[Stephen]

Thanks guys great feedback!!

[EricJ]

3 hours ago, 201er said:

Mine is mounted in the pilot side leg vent indent. Not sure if an F has the same scoop.

 

[Hank]

2 hours ago, EricJ said:

 

Mine is in the copilot scoop, mounted horizontal rather than vertical.

[KSMooniac]

That is the lazy installer (or cheap owner) option...those locations are subject to direct sunlight and radiated engine heat.

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[Yetti]

Starboard wing looking aft.

the nub to the left of the gear center of the inspection panel

 

[201er]

1 hour ago, KSMooniac said:

That is the lazy installer (or cheap owner) option...those locations are subject to direct sunlight and radiated engine heat.

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I would suppose it makes less drag and possibly less prone to icing (if the vent is closed) while giving a pretty good reading. Mine always reads within a degree of AWOS.

[Stephen]

15 hours ago, 201er said:

I would suppose it makes less drag and possibly less prone to icing (if the vent is closed) while giving a pretty good reading. Mine always reads within a degree of AWOS.

Could be an interesting location if it gets clean airflow. 

[carusoam]

Out of sunlight, and away from engine and exhaust heat...

The windshield was OK for the analog gauge, but won't have the proper shared grounding for a display mounted in the instrument panel.

The factory has been installing it under the passenger side wing since the  '90s...

Best regards,

-a-