Engine Monitor Failure?

Lon

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Jul 10, 2019
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73
My RV12 is equipped with dual Dynon Skyview HDXs. Until recently, the Amps and Volts displayed on the SVs were exactly what they were supposed to be. Now though the SVs display negative Amps -- anywhere from -4 to -12 Amps, depending on how many of the plane's components I've turned on -- and declining Volts.

The plane has a Rotax 912ULS engine, and many planes with that engine have this identical battery charge issue. My mechanic has done all of the recommended things. He secured the connections to the Ducati Rectifier/Regulator. He replaced the Rectifier/Regular with a new one, because the old one had blisters on its back. He tested the voltage output of the stator and of the new Rectifier Regulator, both of which were what they should be. He improved the grounding of the Rectifier/Regulator by sanding the firewall to which it is bolted; and he added a ground wire attached to the battery's negative terminal. He changed the Rectifier/Regulator again, in case the first new one was defective right out of the box. He charged the plane's Odyssey PC680 battery. I replaced that battery with a brand new Odyssey PC680 battery.

None of these things helped. The engine starts immediately and runs smoothly. But:

- The SVs still display negative Amps and declining Volts.

- Also, both SVs turn on as soon as the Master switch is turned on, but after just a few moments, the co-pilot side SV blinks off and reboots.

- Finally, the digital checklist I added to the SVs no longer stays on, the way it used to. Now, after a short time, the checklist blinks off and is replaced by the moving map (which is the default item for the right half of my displays).

The only change to my Dynon setup that I've made is that shortly before the battery charge problem began, I installed Dynon WiFi Adapters. They worked fine for a couple of flights, and then my iPad Mini began dropping the WiFi signal.

I now wonder whether my problem is with the Dynon Engine Monitoring System, rather than the plane's charging circuit. That is, I wonder whether the failure of the old Rectifier/Regulator -- or something else -- damaged the circuit that senses, reads and displays Amps and Volts, so the SVs now erroneously display negative Amps and declining Volts.

Any thoughts about what my problem might be would be deeply appreciated.
 
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Raymo

I love aviation!
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Richmond Hill, GA
Sounds like the SV is telling you the truth, that you still have a charging system problem. What voltage do you see at the battery when the engine is running at an RPM sufficient to charge? Should be 13.9 - 14.5 volts.
 

GalinHdz

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Mar 3, 2008
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The SkyView EMS does not have a current (Amps) sensor. Instead it reads and displays the value from an external shunt or an external Hall Effect Sensor. So your external Amp sensor and the internal volt meter are both showing, independent of each other, something wrong with your charging system.

As Raymo posted: "What voltage do you see at the battery when the engine is running at an RPM sufficient to charge? Should be 13.9 - 14.5 volts."
 
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airguy

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Nov 10, 2008
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Gods Country - west Texas
There are numerous tales of charging system problems with the RV12, I would not be too quick to assume the problem is in the Dynon hardware. You should visit the vans builders forum at vansairforce.com and search the RV12 threads there for electrical issues.
 

Lon

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Jul 10, 2019
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Raymo, GalinHdz and airguy: Yes, I now agree with you all. My latest suspect is a Van's component that was part of the RV12 kit, and I've ordered and am waiting for delivery of a replacement part. I was alerted to this latest suspect by another RV12 owner on vansairforce.com. I expect the part to be delivered tomorrow or Thursday and will install and test it the next day. If -- as I hope -- that cures my plane's illness, I'll post the solution so as not to leave an impression on this Forum that it was the Dynon. I first began to suspect the Dynon because when I described my plane's symptoms to a friend who owns a Rotax-powered plane, he immediately said it was the ammeter and voltmeter, not the battery charging system, and that I could "fix" the problem simply by pasting "Inop" stickers over the display. (He was kidding, of course . . . I think.)
 

Lon

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Jul 10, 2019
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The Silent-Hektik regulator is a much better unit than the one supplied.
That's what I understand. In fact, I think Van's may be supplying Silent-Hektik RVs with the RV12iS -- the latest version of the 12. But I've seen at least one online post saying that a Silent-Hektik regulator failed. Even motorcycle owners suffer regulator failures. So, go figure . . .
 

Lon

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Jul 10, 2019
Messages
73
Thanks to all of you who responded. My battery-charging problem was accurately diagnosed by an electrician who owns an RV-12. And the problem had nothing at all to do with the Dynon HDXs in my plane. I had a blown fuse hidden inside a Van's RV-12 switch panel. The blown fuse resulted in my Rectifier/Regulator not putting out any current to charge the battery -- hence, negative amps and declining voltage. I replaced the switch panel, and now my HDX shows that the battery is getting charged again. Happy days are here again.
 
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