No Electrical Power

RV-12, Serial Number 120445, with 912ULS Rotax engine; Dynon: with D1000 EFIS, A/P, ADSB In/Out, GPS2020, Transponder, Pitch and Roll Servos; and, Garmin: SL40 Radio.

Engine starts and runs fine. Dynon EFIS comes alive.

There appears to be no power to the A/P, ADSB In/Out; Dynon GPS2020; Dynon Transponder; Dynon Pitch and Roll Servos; and, Garmin SL40 Radio;and, all the switches from the Trim Switch thru the AutoPilot. All the fuses are good. Engine battery is two years old, appears to be holding a charge and turns the prop easily.

Looked under the cowling and in the avionics bay, and, found no mice or bird’s nest. Looked for loose connections and abraded wiring, found none.

Plane was last flown in late November and was flying properly at that time. It has sat in a hangar from December thru March because of the snow and cold weather. Now, a bunch of stuff is not working. I am not an electronics wizard. Any suggestions would be appreciated.

Is there a relay for avionics?

I assume your fuses are OK?

Avionics Master switch internal failure or associated wiring? You can look at the overall wiring diagram for your version of the RV-12 on Van's Aircraft's website at:

https://www.vansaircraft.com/downloads/#ElectricalSystemDiagrams

Switches need exercise just like people do.
Turn the avionics switch on and off 100 times to wear away the corrosion.

Is your plane equipped with the Advanced Control Module? If so, you should be able to access it through the Dynon EFIS to see what is alive and what is not.

Could very well be like Joe says – corrosion. I’m finishing annual condition inspection after plane sat in hanger all winter. See my post https://vansairforce.net/community/showthread.php?t=213058&highlight=hate. Weather has been dry for a week and I powered-up plane today and everything looks hunky-dory.

I hate moisture on electrical stuff…

It almost sounds like the avionics switch itself is broken.

I've had two Otto switches fail internally -- one time the switch "felt" different when using it.. the other time, I couldn't tell from the outside. In both cases though, it was due to a short circuit and the switch's contacts welded themselves to a contact pad.

I'd check to see if you have power at the switch..and if power is getting through the switch when activated.

I am pretty sure the auto pilot servos do not source power via the avionics switch, so if they actually are not receiving power, that would point towards some other cause.

Corrosion. Check the fuses if you have any. My car shut itself down the other day, it was corrosion in the "engine" fuse.

Belated Thank You to all who replied!

Turned all the panel rocker switches on/off ten times. Got a warm day. Powered the avionics and everything is working again. Took a test flight and all is well.

Thank You!

I wonder if condensation in hanger may have caused problem with intermittent switch contact. See.... https://vansairforce.net/community/showthread.php?t=213058&highlight=hate