Electric elevator trim issue

Good day all,

My electric elevator trim failed today in flight. The aircraft is fairly new to me but I reached out to the previous owner to ask if he had issues with the trim while he owned the aircraft; the trim worked great for him.

The trim failed just after takeoff, so I rejoined the circuit and landed. I parked the aircraft and inspected the trim tab area, no FOD, and the trim worked great on the ground.
I went back up for another flight, again the trim failed shortly after takeoff. I returned to the circuit, landed, and inspected. This time there is no movement of the servo at all.
Before I start troubleshooting this I thought I’d reach out here to see if anyone has had a similar problem.

Thank you for your contributions.

Check the connectors at the trim actuator first and use a 9 volt battery to test the actuator for proper actuation. If both are good then its likely at your stick (assuming the trim switch is located there). You can download an installation manual at the Ray Allen website.

Same here

Mine did the same twice. I then ripped out the micro-molex pins and replaces with d-sub pins. Fine since.
If you still have the micro-molex pins there - that’s a good place to start.

I replied before checking what model you have. I thought I was still in the RV14 forum. Mine was a 14 and several have had issues with the supplied pins. Not sure if this applies to you or not.

could be a bad servo (in the elev), a bad switch, or a wiring issue in the circuit from the main buss through the switch and to the servo. The last is most likely as these parts are pretty robust and don't fail often. an exception would be a hat switch in a stick grip, as those will fail at some point. Intermittency points more to a bad wiring connection.

Larry

Found it!

Looks like it’s a bad connection in a pin or connector. I’ve narrowed it down but now I can’t get it to fail anymore, go figure.
I’ll head up flying and if it doesn’t come back that will satisfy me until I tear it apart during the next annual inspection.

Thank you everyone for chiming in, greatly appreciated.