Trim Tabs
The trim tab motor is located behind the cabinets on the starboard side at the stern of the
master stateroom. They can be accessed by removing the three drawers for minor checks but
for more extensive work the entire cabinet panel should be removed. This involves removing
the six screws which hold the cabinet in place.
Motor Harness Control Harness Function
1 Black Black Ground
2 Yellow White Tab Up
3 Dk. Blue Green Tab Down
4 Green Black Stbd. Valve
5 Red Red Port Valve
Black terminal #1 is ground and is closest to the stern. If power is applied to terminal #2 (yellow
on the motor harness) the pump sucks fluid out of the actuator pistons. If power is applied to
terminal #3 (dark blue on the motor harness) the pump forces fluid into the actuator pistons.
Power applied to terminal # 4 (green on the motor harness) opens the valve to the starboard
piston allowing fluid to pass into or out of the starboard actuator. Power applied to terminal # 5
(red on the motor harness) opens the valve to the port piston allowing fluid to pass into or out
of the port actuator.
There are two control stations for the trim tabs, one on the flying bridge and one on the lower
console, Power to the trim tab system is supplied via a circuit breaker on the lower console trim
tab panel.
To check out the wiring harness, first disconnect all the motor harness wires from the motor.
Next, open the starboard panel on the lower console and attach a jumper from the hot side of
the trim tab power supply circuit breaker to the yellow wire. Now check for voltage between
terminal #2 of the motor terminal block and terminal #1 (ground). The voltage should be 12
volts or more. Repeat the check for terminals 3, 4 and 5. If all terminals (2, 3, 4 & 5) show 12
volts the trim tab control wires are working properly.
Next jumper the lower console circuit breaker and check for voltage on yellow, blue, green and
red terminals of the control switch as follows:
Blue and red should be hot with the port rocker switch in the down position.
Blue and green should be hot with the stbd. rocker switch in the down position.
Yellow and red should be hot with the port rocker switch in the up position.
Yellow and green should be hot with the stbd. rocker switch in the up position.
Finally, remove the jumper on the lower console circuit breaker and reconnect the motor wire
harness to the motor terminal block. Then check for excessive voltage drop across test the
voltage across the circuit breaker.
POM, 13-June-2006