Jump to content

Garmin / digiflight auto pilot wiring help


Recommended Posts



is there anyone on here that has experience wiring the garmin gps aera 700 series bare wiring harness to the ct auto pilot?


Digiflight said that the only wire that goes to the garmin gps is there pin 17 and usually the garmin harness is the blue wire.


red, power.................I know where this goes


black, power ground........I know where this goes


blue, tx1 data out.........According to digiflight i know where this goes (to there auto pilot) pin 17


yellow, rx1 data in........What connects here?

orange tx2 data out........What connects here?

purple, rx2 data in........What connects here?


white, audio right ( i assume these next 3 tie into the pm300 intercom)

brown, audio left

green, audio common


thanks as always for your help


Link to comment
Share on other sites



If you get out the install manual for your Garmin transponder and Garmin SL40 or SL30 com and look at these alongside the Garmin GPS manual it will all start to make sense. You are currently only looking at one side of the equation. The Garmin GPS/Transponder and Com units all have the capability of exchanging data. So the Garmin GPS outputs data to an autopilot so your flight plan programmed on the 700 series tells the auto pilot what to do, (thats a data out line). The Garmin GPS can also receive data from a mode S transponder TIS (traffic) feed and display it on the GPS screen (this would be a data in feed). The Garmin GPS can feed frequency information for airports out to a Garmin SL30 or SL40 (another data out feed) and the Garmin GPS screen could also take data in from an additional traffic source (like a Xaon XRX) and display both TIS and XRX data at the same time.


What you hook up where depends on what model transponder and com you have. If you have a GTX327 (no TIS traffic) you would have no connection to the transponder from the Garmin GPS but if you had a GTX330 (mode S with TIS) then you would have a reason to hook up the wire.


Once the wires are hooked up, you then need to set up the GPS to let it know what you have. This is explained fairly straight forward in the manual (Garmin 696 or 796 are the two I have experience with). SEE APPENDIX D STARTING ON PAGE 147 IN THE ATTACHED GARMIN 696 Manual for an example of how these cables all hook up to the various Garmin boxes. Every Garmin GPS (496, 696, 500, 796 all have the same type information).


I would suggest you make a wiring diagram that shows what you have and then plan the hookups by looking at each book. With a schematic of the wiring and all the manuals laid out on a table it takes only a few minutes for all of it to become crystal clear.


Hope this helps, Adam.


Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...