Hydraulic Trim Tab Problems

General Boats and Motors
1

I am the new owner of a flats boat with broken trim tabs. Here’s what I know:

  1. Hydraulic tabs
  2. I have cleaned all of the connections on the switches and all connections seem solid
  3. When port tab button is pressed I hear a click, nothing happens.
  4. When starboard button is pressed I hear nothing
  5. Reservoir is full

Any ideas where to start troubleshooting?

2
  1. If trim tabs do nothing no movement no sound from HPU:
    Inspect for blown 20 amp in-line fuse in helm controls orange wire.
    Inspect for disconnected or corroded connections on HPU ground wire,
    orange positive wire from helm control, and quick-disconnect plug.
  2. If HPU motor runs but trim tabs do not move:
    Inspect for disconnected or corroded red and green wire connections at
    helm control and quick-disconnect plug.
    The following test can be used to help isolate a malfunction.
    Remove wires from helm control and touch together as follows:
    Operation R eaction
    O range ( + ), blue, red Port trim tab down
    O range ( + ), blue, green Starboard trim tab down
    O range ( + ), blue, red, green Both trim tabs down
    O range ( + ), yellow, red Port trim tab up
    O range ( + ), yellow, green Starboard trim tab up
    O range ( + ), yellow, red, green Both trim tabs up
    If trim tabs function in each of the above combinations, check helm control. If
    during this test trim tabs continue to malfunction, inspect HPU.
  3. If one trim tab operates and the other one does not:
    Inspect for disconnected or corroded red or green valve wire connections at
    helm control and quick-disconnect plug. (Red wire operates port trim tab;
    green wire operates starboard trim tab).
    Reverse hydraulic lines at front of HPU to determine if malfunction is in HPU
    or actuator / hydraulic connections. If after reversing lines, symptom shifts
    to other trim tab, malfunction may exist in HPU. If symptom remains on the
    same side, malfunction may exist with the actuator/hydraulic connections.
  4. If trim tabs go down but will not retract:
    Inspect for low voltage of the battery. Check battery voltage while HPU (or
    another accessory) is running. If voltage is less than 10 volts, valves may not
    open.
    Inspect for disconnected or corroded connections on helm control, and
    quick-disconnect plug.
3

on top of the pump are 2 solenoids
they are what open and close valve to control fluid flow
doesnt sound like your pump is working
jump 12 volts to the pump and see if it spins

www.teamcharlestonmarine.com
www.joinrfa.org

4
quote:
Originally posted by Chasbeau

I am the new owner of a flats boat with broken trim tabs. Here’s what I know:

  1. Hydraulic tabs
  2. I have cleaned all of the connections on the switches and all connections seem solid
  3. When port tab button is pressed I hear a click, nothing happens.
  4. When starboard button is pressed I hear nothing
  5. Reservoir is full

Any ideas where to start troubleshooting?

Chasbeau,

Do you know if they are Bennett Trim Tabs? If so how old are they?

The troubleshooting that BW2150 is good (I wrote it :smiley:) but it left out a step at the end that might apply to you. I have posted the complete troubleshooting below.

You might want to check out this video that covers the system and troubleshooting, http://www.youtube.com/watch?v=7E1kp7gPtz8

Pay close attention to the plug by the Hydraulic Power Unit since it may be corroded and check the unit for water damage.

Let me know what you find and I will be delighted to help you get it going,

Tom McGow
Bennett Marine

Fluid: Automatic Transmission Fluid (ATF) any type. Hydraulic Power Unit is self bleeding, running the Trim Tabs up and down 3-4 times will purge air from the system.

Fuse: 12 volt system use 20 amp in-line fuse on positive. (24v & 32v use proportionately smaller)

Red= Port Valve
Green= Starboard Valve
Blue=Motor Forward (pump pressure)
Yellow= Motor Reverse (pump retract)
Black on HPU=Ground
Orange on Helm=Control Positive

Troubleshooting

1.If one side is not operating reverse hydraulic lines on the front of the Hydraulic Power Unit to determine if the malfunction is in HPU or actuator / hydraulic lines. If after reversing the lines symptom shifts to the other side the malfunction may exist in HPU. If the symptom remains on the same side, malfunction may exist wi

5

And when was the last time someone from Lenco ever responded on this site to a question about one of their problematic systems?

That is another reason why I prefer Bennett trim tabs!

Glad to see you here Tabman!

6

Thanks Loosewire,

I’m happy to be here!

I just moved to South Carolina this summer, so I have to make sure I look after the local guys!

Tom
Bennett Marine

7

South Florida to South Carolina, there’s a pleasant culture shock if ever there was one … :wink:

Just an Old Cracker … With a Gun!

8
quote:
Originally posted by Reelly Old

South Florida to South Carolina, there’s a pleasant culture shock if ever there was one … :wink:

Just an Old Cracker … With a Gun!

You got that right! I hadn’t seen snow in 15 years! But I really like it here, settling in nicely!

Tom

9

Welcome Tom

GW 232GT Gulfstream
150Yam x 2
“3rd Day”
Gen. Chap.1 Vs.9-13

10

Welcome to the Carolinas. I love my Bennetts.

18.5 Baycraft Flats Edition
Johnson 150 Oceanrunner
Wood Driftboat