GRT Horizon 1 GNAV/VOR battle

I just purchased Walter Tondu's beautiful RV7A with the three pack GRT H1HS pkg. As soon as you select a gps flight plan, the CDI needles on any of the displays and the nav sources boxes in the upper left of the screen constantly flicker back and forth. Autopilot also rocks continuously as two data sources must be trying to feed it at once. GRT suggested turning off the analog input from the 430, but that didn't solve it. Any ideas? Here is what it looks like in flight. Did it from first powerup in California and for the next 8 hours across the mountains to Iowa.
http://youtu.be/f_QeV2-UA58

Call Carlos at GRT.

Yea, he got the video on Monday. Waiting to hear some more ideas from him. Thanks.

I assume you've talked to Walter and I've never had that happen on mine but I'd get the manual out and check all the settings in the 430 and the GRT's if the baud rates are different they usually won't communicate but some other wrong settings may cause your problems. I have a switch for mine for EFIS or 430 to A/p so you could try just the 430 to A/P and see if you get the same gyrations from the A/P, that would eliminate the EFIS. Do you have 3 GRT's and what auto pilot do you have and do you have a GPS in your EFIS?, if you have a Trutrak digiflight II vsgv you should have that set to GPSS and GPSV on the display and the 430 to GPS and the EFIS should be set to auto or GNAV and the source should be the 430 on the EFIS(it may have several sources) GRT has the wiring for EFIS to 430 on their web site so download that as you may have wire connection problems or a loose connector. I have 2 GRT's, 430 w, 330, and TT digiflight II vsgv A/p if you need help on settings.Good luck Bob@;pbroadband.net

Thanks Bob, GNS430W/330 with DIGIFLIGHT II VSVG. I have been going through the manuals and wiring. Same issue on ground as in flight.

Sounds to me like you might have different settings in the two displays, but the best suggestion is to call Carlos while you are sitting in the airplane - he can walk you through the setup pages and has a great track record of sorting out folks configurations.

Paul

I have seen this.. it was a configuration issue.. kinda like what you say about two sources.. Of course, I can't remember the details now as it's been 2 years or so that we fixed this issue.

Check and make sure that other screens do not have ARINC sharing turned on.. have only one screen set to "send ARINC data.. " or wahtever that setting is.

Carlos at GRT has been helpful. Appears two of the three boxes were wired incorrectly for the serial output switching from the 430s GPS/VLOC functions. VOR was being fed to all despite GPS selected on 430. So for now, will just drive them with arinc until I can sort through it all. Thanks all.

CopterJohn said:

Carlos at GRT has been helpful.

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There is just simply no way to express how much I appreciate the help I have gotten from Carlos------his knowledge and his willingness to help is above and beyond anything I have ever dealt with.

Actually, this goes for all the folks at GRT.

Gold standard for sure.

GRT

Mike S said:

There is just simply no way to express how much I appreciate the help I have gotten from Carlos------his knowledge and his willingness to help is above and beyond anything I have ever dealt with.

Actually, this goes for all the folks at GRT.

Gold standard for sure.

Click to expand...

Ditto, Ditto, Ditto! The same goes for Sandy! A hearty second for nomination for the Gold standard.

Yea, Carlos methodically worked the issue and now we are on to the next one! A very good first impression that echoes everyones kudos.
I have AFS 4500/3500 in my other aircraft, and last summer Rob Hickman of AFS worked with me a on a weekend to solve and issue generated when the local shop updated the 327 to a 330ES and did not configure the units properly.