Strange loss of GPS

[bernardsv]

I recently let my main battery discharge. This seemed to cause the following caution message to appear - "Backup batt unavail. Backup batt test needed". I'd not previously seen this message, I do have a backup battery for my dual bus system but it is not Dynon. I wanted to remove this 'caution' message and therefore changed the battery monitor to 'No battery installed'.
After exiting and cycling power, I found the 'big X' on the map page showing GPS lost. Since I'd just made a configuration change, I reversed my last step and changed 'backup battery' to 'Yes. After exiting, I now had GPS reception. I repeated these steps, each time I configured battery status to 'No', I lost GPS.

I want to remove the 'backup batt unavail' message but more importantly, understand how this seemingly unrelated configuration change can cause a loss of GPS data.

I am using sw version 15.4.7 and my primary GPS is a Dynon gps2020 at serial port 4, position 1.

 

[jakej]

AFAIK, the 'preferred' position for primary gps is port 5, is there any reason you did not put it there ?

 

[bernardsv]

Port 5 was occupied by a GPS 250 when Dynon produced the GPS 2020 model. The manual illustrates the GPS 2020 in port 5 but says that it can be used in any port. It is configured as the primary GPS source.

 

[Dynon]

This is perplexing. The only thing we can think of - where are you picking off power for your GPS? If you change which GPS is POS1 and POS2, does that make a difference?

 

[bernardsv]

I'll try that configuration and report back with the results.