Bennett trim tabs. Motor runs but no up.

Jobu67

Cadet
Joined
Mar 18, 2011
Messages
7
When I press the control buttons the motors make noise but no movement on tabs. I'm not sure if tabs go down because they are both in the down position. The helm controls are sealed and the connector wire contacts are clean..any help? The boat is a 2002 Pursuit 2865/ Volvo DP. Thanks, Joe
 

Tabman

iboats.com Partner
Joined
Feb 21, 2002
Messages
566
I will be delighted to help you get them working. Below you will find the troubleshooting for the system.

Here is a link to a video that covers the basic system and general troubleshooting http://www.bennetttrimtabs.com/videoplayer.php?vID=10

Here is a link to a video that covers troubleshooting the pump if it runs and a Trim Tab does not move http://www.bennetttrimtabs.com/videoplayer.php?vID=22

Also make sure that the system is getting good power, check and clean both ends of the black ground wire at the pump as well as the other connections. Low voltage could cause this problem.

Take a look at step 3 below, it will walk you through the test I think will isolate your problem. Make sure that ALL the screws are tight on the back of the switch even if they don't have a wire attached, this could be your problem.

Let me know what you find and I will walk you through fixing it.

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 with the actuator / hydraulic lines

2. Is the unit receiving a solid 12 volts? Low voltage will some times cause the solenoids to not open preventing the tabs from moving even though the pump motor is running.

3. Conduct the following test:
Remove the wires from the helm control and touch together as follows:
Operation=Reaction
Orange (+), blue, red= Port trim tab down
Orange (+), blue, green=Starboard trim tab down
Orange (+), blue, red, green= Both trim tabs down
Orange (+), yellow, red= Port trim tab up
Orange (+), yellow, green=Starboard trim tab up
Orange (+), yellow, red, green= Both trim tabs up

If the trim tabs function correctly for each wire grouping then the switch is at fault. Also note that any loose or missing screws on the back of the switch (whether a wire is connected there or not) can cause the pump to malfunction.

This test may also be done right at the pump by substituting a "hot lead" for orange. There is usually a connector to the wire harness within a foot or so of the pump. You want to check this connection for corrosion. You may wish to cut the connector off on the pump side and try the test on bare wires.

4. If you suspect corrosion on the wire connector near the pump, cut it out, test as above and reconnect using butt splices.

5. If you conclude the problem is in the pump, contact me. Bennett Trim Tab Systems carry a five year warranty.

6. Check to see if there is a relay in line on the wiring harness near the hydraulic power unit. If there is it is an Interrupter Relay (IR1000). It prevents the system fuse from blowing if you try to actuate one trim tab up and the other down at the same time. After you test as outlined above, try removing the relay from the wiring harness and retest the unit.(Note: the interrupter relay is no longer used in current Bennett Trim Tab systems and has been replaced with a Switches that "lock out" preventing a blown fuse).
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,308
Ayuh,..... Welcome Aboard,..... Let's get you into yer own thread 1st, insteada this antique reference thread,...

Did ya follow the diagnostics Tom posted in the old thread,..??

Is the oil full,..??
 
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