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Need a Garmin expert

Mike Crossland

Mike Crossland

Member
Ive got a Garmin GTX325 transponder. I installed a new GAE 12 Encoder.
I wired it with Garmin install manual (figure D-1) and have since double checked my wiring.
I get a message on the transponder that says communications failure for altitude.
Before I send the encoder back I was wondering if someone with lots of experience could post a diagram of the wiring to make sure I'm wiring it correctly. and also wanted to make sure I'm not missing something in my reading about any other steps I'm supposed to take.

Thanks for any help.
 
GAE-12 needs to be calibrated IAW install manual before it will output altitude info, pitot static test set required.
 
Mike Crossland said:
Ive got a Garmin GTX325 transponder. I installed a new GAE 12 Encoder.
I wired it with Garmin install manual (figure D-1) and have since double checked my wiring.
I get a message on the transponder that says communications failure for altitude.
Before I send the encoder back I was wondering if someone with lots of experience could post a diagram of the wiring to make sure I'm wiring it correctly. and also wanted to make sure I'm not missing something in my reading about any other steps I'm supposed to take.

Thanks for any help.
Click to expand...

As long as you used the Figure D1 wire colors for the 4 config/encoder and the 325-00421-00 wiring harness, it is pretty hard to go wrong on the wiring. The colors(pins) are RED(43), BLK(23), YEL(22), WHT(1).

Altitude Source 1 should be set to "ALT ENC" and Altitude Source 2 should be set to "NONE".

The Internal Alt Encoder Installed page should have Installed set to "YES" and should specify the maximum altitude ceiling you will calibrate to and the number of calibration points (minimum 3).

The Internal Alt Encoder Adjustment page should be used to calibrate the altitude encoder to the primary altitude source for the number of calibration points you specified. If you do not perform this calibration, the altitude encoder data is unavailable for use (failed). I have only seen the instructions for this calibration in the STC installation manual (not TSO), but maybe a newer TSO manual has this procedure.

None of the serial ports should be configured for an altitude encoder, or you will get the error you are getting.

Steve
 
Last edited:
Longez said:
As long as you used the Figure D1 wire colors for the 4 config/encoder and the 325-00421-00 wiring harness, it is pretty hard to go wrong on the wiring. The colors(pins) are RED(43), BLK(23), YEL(22), WHT(1).

Altitude Source 1 should be set to "ALT ENC" and Altitude Source 2 should be set to "NONE".

The Internal Alt Encoder Installed page should have Installed set to "YES" and should specify the maximum altitude ceiling you will calibrate to and the number of calibration points.

The Internal Alt Encoder Adjustment page should be used to calibrate the altitude encoder to the primary altitude source for the number of calibration points you specified. If you do not perform this calibration, the altitude encoder data is unavailable for use (failed).

None of the serial ports should be configured for an altitude encoder, or you will get the error you are getting.

Steve
Click to expand...

Thank You Steve. I always try and help people if its my area of expertise and I always appreciate it when I get the help from someone.
 
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