Configuration issue or 429 wiring

I have installed the GNX 375 and have either a configuration issue or a wiring issue and would like to eliminate any possible configuration issue before I pull apart the connector wiring.
Setup is Dynon D-100, HS34, SL30, TruTrak Gemini AP, and Aera 760.

Everything appears to be working as expected except for the 375 GPS driving the Dynon HSI, I get a "waiting for GPS fix" on the HSI page for the 375, the 760 (rs232) and the SL-30 NAV (rs232) both work fine and drive the HSI. The 375 429 TX is ganged to drive the Dynon HSI via the HS34 and the TT AP and GPSS mode works fine on the AP suggesting the 375 output is configured correctly (GAMA 1 and Low speed)

On the HS34/D-100 I have the input set to GAMA GPS and speed to low.
I have tried all the available setting and am now wondering if the Dynon is actually receiving a 429 signal input but not sure how I can check.
The good news is that the 429 signals are on their own connector on the HS34 and are only 4 wires.
Any thoughts from the wizzes on VAF, am I missing a simple config item somewhere?
Thanks
Figs

Figs,
I’ve been fighting an ARINC issue too with my new GRT EX EFIS system. It was not wanting to communicate gps data to my TruTrac autopilot through the remote ARINC. I’ve learned that you have to make sure the “ARINC 429 A - Out” is talking to its respective “A” input and that “ARINC 429 B -Out” to its respective “B” input. All “A” wires must be only talking to “A’s” and “B’s” only talking to B’s. I used a multimeter to confirm the correct continuity was established and that nothing was grounded.


With the GRT you can go to “Display Unit Maintenance” and check your ARINC status counter to confirm proper communication. I’m not sure how Dynon does this but I’m sure it’s something similar.

I finally discovered my problem had to do with some “jumper wires” TruTrac installed when I changed my autopilot from the Digitrac II (screen failure) to the Vizion 385 five years ago. I rewired all the connections going to and from my autopilot source selection DPDT switch from the ARINC module which cleared up the problem.

BTW: I HATE WIRING PROBLEMS!