User Manual
Auto Trim Installation Manual  1  TruTrak Flight Systems 
December 2009  8300-013 Rev C 
Electrical Pin-Out 
The table below provides a brief explanation of each pin function on the 25-pin connector P101. 
P101 Pin  Function  Notes 
1  No Connection. Reserved for future expansion.   
2  No Connection. Reserved for future expansion.   
3  Pitch Servo Trim Sensor. Pitch servo trim sensor output to autopilot programmer.  @2.5 v AP engaged no load 
4  Pitch Servo Trim Sensor. Pitch servo trim sensor input from pitch servo pin 7.  @2.5 v AP engaged no load 
5  Torque Control. Pitch servo torque control input from autopilot programmer.  @5 volt, AP engaged 
6  Torque Control. Pitch servo torque control output to pitch servo.  @5 volt, AP engaged 
7  No Connection. Reserved for future expansion.   
8  Trim Switch 1. Line 1 to existing trim switch.   
9  Motor 1. Line 1 to existing trim servo motor. Will not control relays  Voltage in @max 5 amps 
10  Motor 2. Line 2 to existing trim servo motor. Will not control relays  Voltage in @max 5 amps 
11  Trim Switch 2. Line 2 to existing trim switch.   
12  Power. Connects to autopilot master or pitch servo power line from programmer.  11 – 35V input 
13  Power. Connects to pitch servo pin 1.   
14  Ground. Ground connection to link sensor.   
15  Ground. Connect to aircraft ground.  Aircraft ground 
16  Ground. Ground connection to pitch servo pin 9.   
17  No Connection. Reserved for future expansion.   
18  PH1P. Servo drive line output to pitch servo pin 3.   
19  PH1P. Servo drive line input from programmer    
20  PH1N. Servo drive line output to pitch servo pin 2.   
21  PH1N. Servo drive line input from programmer    
22  PH2P. Servo drive line output to pitch servo pin 5.   
23  PH2P. Servo drive line input from programmer    
24  PH2N. Servo drive line output to pitch servo pin 4.   
25  PH2N. Servo drive line input from programmer   
The Auto Trim controller MUST be wired directly to the aircraft trim motor. If the aircraft 
manual trim system uses a relay system the Auto Trim connects on the motor side of the 
relay system. 
Total Weight  Voltage  Current  Trim Motor Output 
.5 LB  11 V – 35 V  .25 A – 5 A  Input voltage / 5 Amps 
25-Pin Connector P101 
1
20 21 22 23 24 25
2345678910111213
14 15 16 17 18 19










