GPS input

[rvbuilder927]

I am trying to connect my D10A to a Garmin GPS III Pilot. It appears that others have done so successfully, but I can't seem to get the Dynon to recognize the GPS. I have the GPS set to output NMEA at 4800 baud (the only rate choice). I have tested the wiring. The Dynon has been updated thru the same female DB9 and worked fine. I have double-checked that the GPS transmit wire is inserted into pin 3 on the new DB9 connector. I have tested for continuity from the plug in the back of the GPS to the pin 3. The Dynon HSI EFIS-Serial is set to NMEA, 4800, but on the HSI setup screen, the list of 9 GPSs does not show any inputs, and the clock on the Dynon does not sync to the GPS clock, and the HSI only shows heading.
I assume that the list of 9 GPSs on the HSI setup screen should show input from one GPS? How else will I know that they are "talking"?
Sorry about the long-winded post.
Any help would be MUCH appreciated.
Ward :-X

 

[Ken_Kopp]

If you Garmin GPS III is running off batteries and you do not have the serial ground wire from your garmin connected to the serial ground on the EFIS DB9 that might be the problem. If your GPS is running off aircraft power and is grounded through the aircraft gnd then something else is the problem...I think.

Ken

 

[rvbuilder927]

Ken,
The GPS is indeed powered by the aircraft system and grounded to the firewall ground block. I went out today and connected the Dynon to the PC, and the PC read the information from the Dynon fine again. I also have the GPS connected to the GTX-327 transponder, but I do not believe that connecting the GPS to two devices should be a problem. I am hoping not to have to disconnect them, as I used crimped connectors . In retrospect, not such a hot idea at this stage.
Thanks for the input!
Ward