Ammeter giving almost random readings

[prhutson]

In an install of a D10 in a Glastar, substituting for a Westach analog that read amps nice and stable, I am also having erratic +/- readings on the D10 with the "A" configuration of discharge/charge.  Is an electrolytic capacitor the answer?  A 1mv/amp shunt is also mentioned in this thread.  Is that advised, and if so, how is it or the capacitor installed?
Thanks
 

 

[dynonsupport]

So first of all, what are you connecting the amps wires to? A shunt? Something else?

 

[prhutson]

Sorry for the delay in responding - was out of town.
I am replacing the Westach ammeter that was connected across the shunt. I am using new cable, and have soldered in 26Ga wire on both leads as fusible links.

 

[BigJohn]

Interesting to see this thread pop up again. I see the same wild fluctuations in my D180 installed in my RV-12. Always have. I've just gotten used to it. I've gone thrugh all the usual detective work - no joy. As to the capacitor(s) - I had too much alternator whine on my intercom, and to try and tame that down a bit I installed a second 22,000 mfd cap on the firewall, right next to the regulator. That did help with the intercom noise, but the ammeter fluctuations remain. Some of my other displays wiggle around a lot too. Basically I think the Rotax alternator is very noisey, and this caused a lot of problems with the Dynon sensors. I wonder if the same symptoms occur in the Skyview, or if they have come up with better filtering/sampling.

 

[prhutson]

Hi, John.
My D10 issue is with a Lycoming O-320. I thought that the 2 conductor wire going across the bottom and back of the panel might be acting like an antennae, but I didn't see the +/- jumpiness with the same course using the analog Westach ammeter, and I can't figure what might be causing the pulsing. Maybe it is picking up the transmissions from my old Narco transponder cavity? I'll fly out of Class Charlie and see what happens when I shut down my xponder and report. In the meantime, any other suggestions are appreciated.