Electrical? Issue
Posted: Sat May 25, 2019 1:38 pm
So my plane has not been playing nice. I have a Rotax 912 ULS. A couple of weeks ago I went to fly and when I flipped on the radio, no sound. I checked and the headset was jacked in. When I went to unplug it as soon as it was half plugged in I had sound. Shove it in all the way, no sound. Called the Unicom and verified they could hear me. Taxied over to pick up a passenger. They plugged in their headset and nothing. I couldn't hear them and they couldn't hear me. Went flying and no other apparent issues. Went flying the following week and I'm cruising along at 4800 RPM and I get a low volt warning light. The volt meter drops back to about 12 volts. It lasts a few minutes then the light goes out and the voltage goes back up. A few minutes later and this happens again. When I search out the symptoms I find posts that seem to indicate it's either a loose wire, corrosion on the connector to the voltage regulator or a bad voltage regulator. I have a look, I have a Ducati voltage regulator(apparently there is a newer model). All the wires seem tight. I unplug the wiring connector and verify that there is no corrosion on the connectors. I clean off the contacts with some cleaner and hook things back up. I try and test it out again today. Same issue with the radio my no low volt light and the volt meter is looking good. As I'm taxing to the run up area, the low volt light comes on and I hear a "buzzing" sound from behind the instrument panel. The low volt light is flickering seemingly in sync with the buzzing. My radio sound is cutting out as well. I taxi out of the way and see what's going on. Well the light goes out, the volts go back to normal and the radio is working as it had. I taxi back to the run up area, do my run up and take off. Just about as I do the voltage drops below 12. I was staying in the pattern so I bring it around and land. As I taxi back to my parking spot the voltage is below 12 but no low voltage light. I get back to my spot and shut down. I have a look under the hood and nothing has changed. I'm thinking at this point I probably need a new voltage regulator. There is one other device I don't know what it is but I'm wondering if the noise I heard was coming from it. In any case I start up again and now the voltage is normal, no low volt light and no buzzing. I run it for a while and even load up the system(lights, radio, transponder, standby pump all on). Voltage stays above 12 at 4000 RPM. For shits and giggles I try the passenger headset and low and behold it's working now. I check mine and I can fully seat the jack and things are find. I'm probably going to try some more flying in the pattern to see what's going on with the voltage but anyone have any idea what could be causing this? Should I just replace the voltage regulator? What the other device? Very confused.