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Cheap way to hardwire a GDL-39

bullojm1

Well Known Member
I purchased a Garmin GDL-39 ADS-B receiver a few weeks ago. I want to hard wire the unit into my airplane, but the cable included was meant to connect to a cigarette lighter powerpoint. I could chop up this cable, but I'd rather not so I can run the GDL-39 from home if needed. I looked into how much a "Bare Wire" kit was for the GDL-39 and I was blown away -- $65 smackers! Time to reverse engineer this cable to see if I can save some money.
DSCN3040.JPG


The first step was trying to identify the connector type Garmin used. I lucked out and determined it wasn't proprietary - a

Hirose 18 pin Connector. Bonus was it was readily available from Mouser.com. The Mouser part numbers for this cable are



18P CBLE PLUG STD: "ST40X-18S-CV(80)" -- $5.71

CABLE BUSHING: "ST40X-BS(4.0)" -- $0.63





So for $14 shipped, this was looking better than $65.
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The next step was determining the pinouts. With a multimeter this was a simple task. Here are my scribbled notes.
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A little more detail. This is the connector side. Note the pinouts for ground should be (6,8,9,18)
DSCN3043.JPG


And the solder points for the "Single Key" side of the connector.
DSCN3044.JPG


And the "Dual Keyed" side of the connector.
DSCN3045.JPG


I wired it all up and it works flawlessly. The soldering isn't the easiest in the world since it's easy for the solder to bridge the conductors on the plug. I placed shrink wrap around each pin with a wire soldered to it because the pins tend to bend slightly. With the casing on, this seems like a solid solution. Next step is wiring it up to the RV.
DSCN3046.JPG
 
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Good Idea

I have the bare wire kit, but I think I'll make one of these up just so I can bring the GDL39 home, hook it up to a battery, and a Nexus 7 and do updates over wifi.

-John
 
In my hand-drawn pinout, the transmit and receive off of the 696 connector are located, indicated by "SIG1" and "SIG2". I don't know which one was transmit and receive, and I had no way of testing it so I didn't include something I couldn't verify into my writeup.
 
Bare Wire GDL39 connector

I have the bare wire kit

Boomer or anyone else with the bare wire cable, Garmin X dudes, perhaps, any chance you can ring out the pins and wires on this for us? The GDL39 guide is no good for the bare wire harness. Specifically at the connector end. Thanks folks
 
In one of the pics above with the numbering, it appears the text is correct (6,8,9,18) but the RED numbers on the picture show 8,8,9,18. No biggy, just wanted to clarify potential confusion. To add to what we see here in an effort to ring out some of the pins, it appears from the 696 manual and based on the orientation of the denoted pins that one can make an assumption on SIG IN and SIG OUT. I'm gonna give it the old college try at some point today. Here's the pic.

connector_zps6e672917.png
 
pin outs on the bare wire

ok. after many attempts at trying to solder those blasted little pins with marginal success and then stepping back for a second and recognizing that my marginal job was providing the datalink to traffic and weather, I decided to leave it to the capable hands of the folks at Garmin. I ordered the bare wire cable. The connector plug and housing cited in previous posts is an exact match. Here is what I found when I rang out the 18 pin connector

1- red
2- red
3-
4-
5-
6- blk
7-
8- blk
9- blk
10- wht/green
11- green
12- grey
13- wht/orange
14- orange
15-
16-
17-
18- blk

There are some patient skilled people making these connections...sadly, gladly, I am not one of them.
 
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Bringing this thread back from the dead...

Did you guys connect all of the "black" and "red" pins together or just terminate your wires on a subset and assume the remainder were connected together inside the GDL-39?

Thanks,
David
 
The bare wire cables I used had 1 red and 1 black which fed 2 and 4 pins respectively. I suspect, at least for the power, it's to allow more current than a single pin can handle.
 
Big thanks to MeGiron for the info. I ordered a few of the connectors from my supplier and made my own bare wire cable. I work with electronics and build circuit boards for a living so making the cable was easy for me.

I joined pins 1 and 2 together inside the connector so there is only one red wire coming out of the connector. Did the same with the black.

I have wires for all the pins except pin 12 (grey wire) as it's only needed for remote on/off. I have the GDL-39 wired to my avionics switch so the Aera 660 and the GDL-39 turn on and off with that switch.

Saved a bunch of cash over buying the Garmin cable and it took about 20 minutes to make.
 
Bringing this thread back from the dead...

Did you guys connect all of the "black" and "red" pins together or just terminate your wires on a subset and assume the remainder were connected together inside the GDL-39?

Thanks,
David

Bringing it back to life AGAIN :D I opened the factory cigarette lighter plug cable that just powers the GDL39 ( and Aera 5xx series GPS and other NUVI GPS ) and found that Garmin has 4 wires coming out for power so apparently they don't connect all of the grounds or power pins together.

I ordered a couple of the connectors today but not even their datasheet shows the pinouts, but they connect as you can see in the picture I attached:

Power: 2 end pins on each side (Single Keyed and Dual Keyed sides)
Ground: 4th pin from the power pin on the Single Keyed side and 5th pin from the power pin on the Dual Keyed side

Based on what Mike Bullock (bullojm1) and Mark Giron (MeGiron) posted, and on what I found when I opened mine I believe the Single Keyed side pins are 2,4,6,8, etc and the Dual Keyed side pins are 1,3,5,7,9, etc

SO then the Data Pairs should be:
Pin 10 Receive A
Pin 11 Txmt A

Pin 13 Receive B
Pin 14 Txmt B


UPDATED Mouser part numbers and prices on 9 JAN 2022:

Connector -
Mfr.: Hirose Electric
Mfr. #: ST40X-18S-CV(30)
Mouser #: 798-ST40X-18S-CV30 $3.68

Cable Bushing -
Mfr.: Hirose Electric
Mfr. #: ST40X-BS(4.0)
Mouser #: 798-ST40X-BS4.0 $0.55

.
 

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I connected the two 12v pins together and all the grounds together to only have one power and one ground coming out of the connector. It's been working perfectly since I made the connector back in 2016. Still using it today and actually was at the airport today updating my Aera 660 which automatically updates my GDL-39.
 
I connected the two 12v pins together and all the grounds together to only have one power and one ground coming out of the connector. It's been working perfectly since I made the connector back in 2016. Still using it today and actually was at the airport today updating my Aera 660 which automatically updates my GDL-39.

Yes, I was just trying to clarify a little more the connector and the data pinouts and I also updated info on the prices too.
 
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