ColoCardinal

Well Known Member
The Garmin ADS-B receiver wiring harness includes a connection for DC power, Rx-a, Tx-a, Rx-b, Tx-b and two ground wires. Per the diagram included with the device, the ground wires are associated with the Tx & Rx circuits. I do not see a ground for the power supply side of things.
Anyone know what I'm missing here?
Thanks.
 
Carl, what are you doing up so late? Sorry, I don't know the answer to your question. Good luck!
 
My GDL 39 bare wire cable has power, GND, switch, tx1, rx1, tx2, and rx2.

The switch is if you want/need a manual on/off switch that is independent of simply applying power to the device which does the same thing.

I wired power to my avionics bus/switch. GND to ground, and tx1/rx1 to my 795.
 
Woke up and this unresolved problem kept creeping into my thoughts.

Humpty, You only have two wires connected to your serial comm (Tx, Rx)? and the ground (black wire) connected to Chassis ground? My unit won't communicate and that's the way that I first had it connected. Maybe it's a setting! Hmmm. I'll need to look at this again when I return from the coal mines this evening.

Thanks guys.
 
GDL39 Connection to G3X

The Garmin ADS-B receiver wiring harness includes a connection for DC power, Rx-a, Tx-a, Rx-b, Tx-b and two ground wires. Per the diagram included with the device, the ground wires are associated with the Tx & Rx circuits. I do not see a ground for the power supply side of things.
Anyone know what I'm missing here?
Thanks.

Hello Carl,

Page D-12 of the G3X Installation Manual (Rev. G) shows how to connect and configure the GDL39 to your G3X system with the bare wire cable.

As shown in this wiring diagram, you will not be using the TxB, RxB wires.

Let us know if you have additional questions.

Thanks,
Steve
 
Steve, one thing confuses me with the diagram you referenced. It shows a 3A circuit breaker. The GDL 39 specifications say 3.5W max (8W max if charging the optional battery). That would require less than a 1A circuit breaker.
 
GDL39 Fuse

Steve, one thing confuses me with the diagram you referenced. It shows a 3A circuit breaker. The GDL 39 specifications say 3.5W max (8W max if charging the optional battery). That would require less than a 1A circuit breaker.

Hello Glen,

You are correct on the power draw. The GDL39 bare wire cable is shipped with a 3A fuse which is sized to protect the wire.

You could certainly use a 1A circuit breaker - especially if you are installing it without the battery pack, or just continue to use the fuse supplied with the harness.

Thanks,
Steve