GTX 327 Connector Plug Access

-8A with a Garmin GTX-327; nearly 1200 hours over nearly eight years. Decided to take the ADS-B plunge with an echoUAT/SkyFYX Ext installation.

For optimum operation, the echoUAT instructions say to connect the echo Pin 4 wire to the GTX-327 Pin 20. Even though the 327 is the bottom box of my avionics stack, I cannot easily access the back connector. I can contort my 75+ year-old body enough to get to it but worry about whether I'd be able to reconnect the thing.

John Stark of Stark Avionics did my initial avionics wiring. He suggests going through the front of the tray and loosening the four screws holding the backplate thus lowering the connector for access.

No problem doing that but I again worry about being able to properly align the backplate to reconnect it.

Shane at EchoUAT support says the hardwire connection to the 327 isn't absolutely necessary and not connecting it will result in only marginal performance loss. Not worth the risk of screwing up the transponder.

Anyone have experience/ideas?

If it was me, also 70 and hard to get under the panel i would leave the 327 alone a d use the echo set up that allows it to receive altitude and code wireless a d never crawl under that panel. I hooked up couple echos both ways . No problems with either.

pvalovich said:

John Stark of Stark Avionics did my initial avionics wiring. He suggests going through the front of the tray and loosening the four screws holding the backplate thus lowering the connector for access.

No problem doing that but I again worry about being able to properly align the backplate to reconnect it.

Shane at EchoUAT support say

Click to expand...

While I don't have experience with the 327, I have pulled the backplates on 430's and SL30's. Being that they are all Garmin, I expect the 327 to be the same. It's very straight forward and if you have any slack in wire bundles feeding these units, the job should be straight forward. The backplates are self-aligning and the plate contains the alignment pins, so it's not a precision fit to the frame. The only challenge is putting them back in. If the screws are not SS, a good magnetic screwdriver makes this pretty easy. If you're struggling, replace the 4-40 or 6-32 SS screws with steel. they are 100* tapers, if CS, though. A bit of grease on the screwdriver tip will also hold the screw on the tip.

Once the backplate is out, it may be easier to pull the connector off the back plate. Just two screws and also self-aligning.
Larry

Agree to go wirelessly, at least initially. If you are not pleased with the performance, hardwiring is still an option.

BTW, I have an Echo UAT/GRT Safefly GPS talking with a 327 with no connectivity issues.

pvalovich said:

He suggests going through the front of the tray and loosening the four screws holding the backplate thus lowering the connector for access.

Click to expand...

You don't need to removed the backplate to release the connector. Looking down the empty tray, in the back there is a ~1/2" long phillips screw on either side of the connector. Unscrew those and the connector is released from the backplate. I have no idea how you will get the connector and die-cast "keeper" back on, though, or whether you will have room to work on it. I posted some photos that might help on this thread:http://www.vansairforce.com/community/showthread.php?t=166994 Good luck!

snopercod said:

You don't need to removed the backplate to release the connector. Looking down the empty tray, in the back there is a ~1/2" long phillips screw on either side of the connector. Unscrew those and the connector is released from the backplate. I have no idea how you will get the connector and die-cast "keeper" back on, though, or whether you will have room to work on it. I posted some photos that might help on this thread:http://www.vansairforce.com/community/showthread.php?t=166994 Good luck!

Click to expand...

Yes, I just did this. Decided to hardwire the #20 pin to the EchoUAT. Just loosen those two screws from the front with a long Phillips screwdriver, and then you can pull away the D-sub connector/keeper from the tray.

I suggest leaving those two screws in place, as it makes reassembly easier.

rightrudder said:

I suggest leaving those two screws in place, as it makes reassembly easier.

Click to expand...

That would have been smart, but I didn't do it that way. What I did was use a little piece of blue painter's tape to hold each screw on the end of the Phillips screwdriver. After the screw had started, I pulled out the screwdriver and reached in with some hemostats to pluck the tape off the screw head. That worked pretty well.

snopercod said:

That would have been smart, but I didn't do it that way. What I did was use a little piece of blue painter's tape to hold each screw on the end of the Phillips screwdriver. After the screw had started, I pulled out the screwdriver and reached in with some hemostats to pluck the tape off the screw head. That worked pretty well.

Click to expand...

Yes, the blue tape trick has worked many times for me! A really good magnetized screwdriver is also an option.

Interesting coincidence; I'm currently troubleshooting a new to me install of AFS4500s with an old 430 & a 327, and pin 20 showed up in my troubleshooting.

I'm able to work on mine on the bench; the panel unplugs completely (HIGHLY recommend that...). If I couldn't, it would be a real bear to work on any of the Garmin tray connectors. It's a real shame that the backshell can't come off without completely removing the connector (from inside the tray, of course). I really wish that the Garmin engineers/designers had to install their own stuff, and then make changes to the installations. They'd realize that there are better ways...

Charlie