adhars intermittent failure

[GeorgesGolf]

I just make my first engine start but not yet flown.
I have 2 skyview touch with 2 adhars (purchased in July 2016) and on one of them sometime the speed bar flicker with a bad indication of speed witch should be 0 in the hangar.
When it happen pitch is slightly wrong also and sometime I get a message VPX fail because skyview think I am in flight without alternator.
It is not a permanent failure but more and more often now.
Any idea?
Thank you

 

[airguy]

Have you done the zero-airspeed calibration routine?

 

[GeorgesGolf]

Zero airspeed calibration is done.
Speed indicate 0 in the hangar when the 2 adhars work properly.
I suspected a bad electric connection but after changing the plugs the malfunction is always on the adhars 200.

 

[swatson999]

Zero airspeed calibration is done.
Speed indicate 0 in the hangar when the 2 adhars work properly.
I suspected a bad electric connection but after changing the plugs the malfunction is always on the adhars 200.

Can you swap the units to see if the failure follows the unit, or stays with the wire?

 

[GeorgesGolf]

I changed the wires between the 2 units and failure stay on the adhars 200.

 

[swatson999]

I changed the wires between the 2 units and failure stay on the adhars 200.

Did you change the wiring harness at the ADAHRS end? Or at the EFIS end?

 

[GeorgesGolf]

At the adahrs end.
Wiring goes from the adahrs to a splitter and from the splitter to the SV-NET-HUB.