Lost my trim position display

Started up this morning and trim position indicator had disappeared from my D180. Trim is working normally. Everything else on the EFIS page is unchanged. Not having built the aircraft, I'm not sure where to start looking. Is it likely to be settings issue with the 180, or the loss of a connection? I'm gradually coming to understand the inner workings of the 180 but still not proficient on options deeply embedded in the menus. Recently I managed to make a display change in the EMS, replacing an OAT display with an amps indication (next to voltage). Just in case there was a connection I reversed that after trim indication disappeared, but to no avail.

Jack

Do you have the FlightDEK-D180 Installation Guide?
Read "Trim Calibration" on page 6-6 and Elevator Trim on page 6-17.
If the D-180 configuration is correct, then check for bad connections at the servo in the tail.
Do you have an easy to read version of the RV-12 D-180 SCHEMATIC?
There are a total of 5 wires connected to the trim servo. 2 of them power the motor when the trim switch on the instrument panel is pressed. Those 2 wires are not the cause of the trim indication problem.
The other 3 wires connect to a potentiometer (pot) inside of the servo and sense the servo position. The power circuit and pot circuit are completely independent of each other. Measure the voltage between those 3 wires. Do not use the airframe as a reference point. Two of the wires should have 5 volts between them. The third wire should have a voltage somewhere between 0 and 5 and that voltage will vary with the servo position.

Got it back

Thanks, Joe, for your very helpful reply. Turns out that I had inadvertently turned off the trim display when fiddling my way through the menus. All good now. Thanks especially for the information on voltage at the servo. I was in that area to identify the wires a few months ago when my trim "failed". All the connections were good and I was starting to think I might be up for a new servo. I decided to have a look at the wiring up front first and fortunately noticed that the rate controller had been wound back to zero. The previous day my avionics guy had been looking over the plane in preparation for a new GPS install. He asked me what the controller was (at that stage I didn't know) and then must have proceeded to adjust it. Can't work out what he was thinking. Luckily I had photos that allowed me to take the setting back to where it had been previously.

Jack