G3x setup, ADAHRS and Transponder not working

[stuartbw]

I've completed a build on a model 7 SS with a Rotax 912 ULS. For some reason, the G3x will not recognize my transponder GTX45R. The connections are sound, the harness was wired by Stein. Has anyone else had this problem? The ADAHRS (GSU25) is also not registering with the G3x, even though the green light is on on the back and it seems fine otherwise.

When I contacted Garmin, the asked me to recheck the wiring, which is fine. I'll call them again.

Brett
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Building Model 7 SS, Rotax 912ULS

[Kitfoxnut]

I have a friend at the airport that built a RANS S-21 that ran into the exact same problem. He wound up doing a software update with all devices connected and things started working properly.

Hopefully this is helpful

Lee

[Dave S]

Might want to give Stein a call since they made the harness; and, they are wizards with Garmin products and experimental aircraft.

[desertdave]

Garmin tech support was my first option on the first problem and they were of no help. Since I got my entire G3x setup from SteinAir I called them next and their customer service is nothing short of amazing. I had a few questions and they walked me thru all of them.
I do recommend you pin out every plug. I found one plug that 2 wires were reversed. It wasn't a big deal but none the less people are human and stuff occasionally happens.
As for the software update, that is where I would start too.

[TRegli]

I had a GTX35R and had this same problem. Did a software update on the G3X (after calling tech support a couple times they recommended this) and it found the transponder no problem.

[stuartbw]

So I updated the software which did not solve it. I've talked with Stein who confirmed the settings are correct and the box has power. They asked me to confirm the pins are wired correctly (but said that is unlikely) between the transponder and ADAHRS box (gsu25).

I've emailed the G3xpert email at Garmin. Nothing yet....

Maybe a bad box?

[Billiken]

I was following your thread and I thought you had solved the problem. I may have read another thread with the exact same issue. The fix was that two pins were reversed from the pre wired harness. It may be the same problem, especially if they are both from the same supplier. Just thought I’d mention it. Good luck!

[patrick.hvac]

Chances of a bad box are very low.
Sounds like a CANBUS issue.
I can try to help you but I need much more information.
Do you have CAN with serial backup to all available devices?
Do you have the CAN termination resistors in place?
Show the CAN network and electrical diagram.
What does the device connection screen show?
Did you configure the devices properly?

Probably easier to do a video call or something to go through it. Troubleshooting electrical through a forum is very difficult.
PM me if you want to set something up and I will try to help.

[stuartbw]

[Solved!]
Traced the wiring and found a pin that was misplaced. Moved the pin and the system is working!

Thanks for your thoughts and offers to help!

Brett

[desertdave]

Great news!