How do you troubleshoot Trim Tabs?

bbtopcat1

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Port trim tab on my '02 Voyager is inoperative. Stbd tab works fine. The corresponding switch on the two-rocker switch panel has no spring action & there's no actuation noise coming from switch or pump. Have tried to troubleshoot w/ power on the boat trailered w/ either engine running on flushing attachment. Under these trailered conditions, neither port or stbd tabs operate - hmmm? Will be grateful to learn what troubleshooting techniques should bet taken & the probable cause of defect. Finally, is this a DIY item?

Thanks/Brad
 

Parthery

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No need for the motor to be running...the tabs are a completely independent system.

If the spring action in the switch is gone, it sounds like the switch is bad. You can pop the plastic bezel off, remove the switch, and reverse the wires. If the other side works, the switch is bad. If you own a volt/ohm meter, you can also test it that way.

Bennett has excellent customer service. I'd reach out to them. My own experience has been that when my switch went bad, they replaced it, under warranty, no questions asked.
 

Tabman

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bbtopcat1 said:
Port trim tab on my '02 Voyager is inoperative. Stbd tab works fine. The corresponding switch on the two-rocker switch panel has no spring action & there's no actuation noise coming from switch or pump. Have tried to troubleshoot w/ power on the boat trailered w/ either engine running on flushing attachment. Under these trailered conditions, neither port or stbd tabs operate - hmmm? Will be grateful to learn what troubleshooting techniques should bet taken & the probable cause of defect. Finally, is this a DIY item?

Thanks/Brad


Brad,

This is certainly a DIY item and I will be delighted to walk you through fixing the system.

Lets start with the fact that the system does not work at all when the boat is on the trailer. I suspect that there is corrosion in the electrical connections that is reducing the voltage getting to the pump. It would be a good idea to clean all the electrical connections, particularly both ends of the black ground wire at the pump.

sys.jpg



It does sound as if the switch has failed. It is easy to test.

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 if one Trim Tab does not move http://www.bennetttrimtabs.com/videoplayer.php?vID=15

Take a look at step 3 below, it will walk you through the test I think will isolate your problem. Also pay particular attention to the red wire since it opens the valve for the port Trim Tab.

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).
 

jaydub

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Tabman, you continue to set the standard for customer service.
 

bbtopcat1

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Tabman,

You are the true tab"Meister". Greatly appreciate your detailed troubleshooting procedures. After reading procedures and viewing the videos I was able to isolate the fault to a bad rocker switch (left sw), which I now understand operates the stbd tab. Took those corresponding wires (blue/green) and tested the solenoid/pump operation via the right sw connectors and tabs work fine - good solenoid click/motor hum.

Thanks again shipmate.
 

bbtopcat1

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Parthery,

You were spot on. As you recomm, switched wires and isolated problem to a bad switch.

Many thanks/
Brad - 248 Owner of "Liberty Risk"
 

grady23

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Ever since I came on this site a number of years ago, I've ALWAYS been delighted that TABMAN and Bennett have been here to help. We don't see many posts by him BUT he is always there waiting to help. Sir, what ever your real name is --- THANK YOU from all of us. If you decide to retire, PLEASE PLEASE -- Make it a pre-rec that your replacement is your clone !!! Thanks again for all the great support you have provided. If we ever meet somewhere, I will buy you a beer or even 2. :D