John Deere Update
My wife's RV-12 ELSA originally had an under-the-panel $180 Ducati voltage regulator that lasted 120 hrs, followed by a JD $20 replacement that failed yesterday after 150 hrs.
Five minutes after takeoff I smelled hot electrical insulation, the EFIS lady screamed "warning," the voltage digital readout flashed red 29.9 volts, and I instinctively grabbed and removed the 30A generator fuse while wisps of smoke flowed from the center panel.
A friend flying from the left seat turned off the master switch and controlled the airplane while I tried to figure where to aim the fire extinguisher. Simultaneously I pondered why the light smoke continued with everything but the Dynon backup battery deactivated. Then I realized the generator fuse probably disconnected downstream of the VR, meaning the generator was still feeding it. Yanking the wires off the VR killed the smoke. We restored the master and flew home using the ship's battery.
Fortunately when I bought the JD unit, I bought a spare too. Also I installed nutplates to mount it. Putting in the spare, working only from under the panel took ten minutes. During a flight today, the new JD produced 14.1 vdc.
The first JD unit was a bit flakey during its life as the buss voltage varied from 14.0 to 14.4 vdc regardless of load. Its temperature also varied from warm to hot, but usually showed 140F on a non-contact thermometer. So when the voltage began to work higher over the last few flights, I thought that it was normal variation for this VR. Finally it settled at 14.7, which is the top of the charging range acceptable to Odyssey.
Now I realize that the rising output was warning of coming failure. When I see that again, I will prophylactically put in the new spare that I just ordered from Amazon.
RV-10 - 95% complete project For Sale
RV-12 - built for wife now flying light sport
SeaRey flying 2012 - Sold 2017
2017 Contribution made
Last edited by bruceflys : 11-29-2017 at 02:21 PM.