Installation Guide User Manual
Transducer Installation     
TRIM AND FLAPS POSITION POTENTIOMETERS 
Dynon Avionics does not sell trim or flaps 
position sensors. These are normally included 
with, or added on to, their respective servos. 
Most flap and trim sensors are potentiometers 
(variable resistors) which require power and 
ground inputs, and supply an output that is a 
function of position. These potentiometers 
come in a variety of resistance ranges, but are 
typically 1kΩ, 5kΩ, 10kΩ, and 20kΩ. All of 
these values will work properly with the 
EMS-D120, as there is a calibration required, 
as described on page 5-6. Connect the 5V 
Excitation line from the EMS-D120 37-pin 
EMS connector to the +5V input on your 
trim/flap position sensor. Connect the ground 
input on the sensor to a ground common to the EMS-D120. Connect the output of the sensor to 
the desired GP input. You may connect up to three trim/flap sensors. For physical installation, 
refer to the instructions that came with your position sensor. 
If you are using the output from a Ray Allen servo or sensor, connect its white/orange wire to the 
Dynon 5V excitation line (pin 18), its white/blue wire to ground, and its white/green wire to your 
GP input of choice. 
Be sure to configure the EMS-D120 to recognize the various sensors on the general-purpose 
inputs as described in the General Purpose Inputs section on page 5-17. Additionally, you will 
need to calibrate each flap/trim sensor as described on page 5-6. 
DB37 
EMS 
Pin 
EMS 
harness 
Color 
Position 
Pot 
Function  Function
Desired 
GP 
input # 
See chart 
on page 3-
13 
Position 
out 
(voltage) 
GP 
18 White/Red +5V in 
Position 
sensor 
power 
Ground 
pin 
Black 
3-16 EMS-D120 Installation Guide 
COOLANT PRESSURE SENSOR 
You will find two 1kΩ resistors (color bands: 
brown, black, black, brown, brown; connect in 
either direction) in the accessories package (Dynon 
P/N 100446-000) included with the EMS-D120. 
You will be using one of these resistors for proper 
installation of this sensor. 
Ground in 
(common 
to EMS) 
ground 
DB37 
EMS Pin
EMS harness 
Color 
Function
Desired 
GP input 
# 
See chart on 
page 3-13 
The Dynon-supplied coolant pressure sensor is a 0-
30 psi sensor (Dynon P/N 100411-000). First, mount 
the pressure sensor to a fixed location using an Adel 
clam
p or other secure method. The pressure sensor 
must not be installed directly to the engine due to 
potential vibration problems. Next, connect the 
sensor to the coolant line using appropriate hoses 
and fittings. Its pressure port has a 1/8-27 NPT pipe thread fitting; you may need adapters to 
connect to the pressure port on your engine. Locate (or drill and tap) the pressure port along the 
coolant line. This port must have a pressure fitting with a restrictor hole in it. This restrictor hole 
GP 
18 White/Red 
5V supply 
to 1kΩ 
resistor 
Ground 
pin 
Black 
Ground in 
(common 
to EMS) 










