TruTrak Automatic Pitch Trim - Manual (Page 8)

Auto Trim Installation Manual 5 TruTrak Flight Systems
December 2009 8300-013 Rev C
Manual Auto Trim Switching with Auto Pilot Engaged
Trouble Shooting
Problem Cause Corrective Action
Trim motor will not move
with control pressure and
manual trim control is
functional No aircraft voltage and/or
torque voltage to auto trim
system Correct power, ground, &
torque wiring
Engage auto pilot before
testing
Trim motor will not move
& manual trim control
nonfunctional Trim sense voltage incorrect
with auto pilot engaged
from pitch servo pin 7
Check 2.5 voltage at pin 3 or 4
Voltage will increase or
decrease with elevator
pressure
Trim motor only runs in
one direction Auto trim motor control
wires not connected to trim
motor (relays). Auto trim motor control wires
must be connected to the trim
motor only.
Trim bar briefly shows on
autopilot display Auto trim controller speed
too slow Rotate knob on controller
clockwise
Aircraft hunts up & down
in pitch Auto trim controller speed
too high Rotate knob on controller
counter clockwise