Tabs won't move??

MikeWood

Member
Jan 19, 2012
114
Seneca Creek, Baltimore
Boat Info
2008 270 Amberjack
Engines
6.2 MPI & Bravo III
I just had my boat hauled for the winter season, but a couple weeks ago when I was out my tabs stopped moving. I was at the boat today and had the engine hatch open so could hear the motor better. The motor sounds normal when I press the buttons to raise the tabs. But the tabs are already up, so they don't move. When I press the buttons to move the tabs down, I hear the motor for maybe a half a second, then it quits and I hear nothing. If I go back the other direction and repeat the process, I get the same thing. Half a second, then nothing. Doesn't seem to matter which switch, port or starboard, I get the same results.
Any thoughts on these symptoms? I'd love to get them fixed now so I don't have to worry about them in the spring.
 
The very first thing to check is both ends of the black ground wire at the pump to be sure they are good and clean. Then do step 3 in the troubleshooting below both at the switch and at the pump. Let me know what you find.

Tom
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).
 
Hey Tom,
I didn't mess with this problem in the fall, so I'm just getting back to it now. I just ran test #3 at the pump. It acts the same when I do that as it does when I use the switches. The good thing about working at the pump is I can hear it better. Sometimes, no matter what connection I make, the pump clicks for a split second, then does nothing. Other times, the pump will spin. But it only spins in one direction (lifting tabs up). When all it does is click, it really sounds like maybe the pump is locked up....not sure if that makes any sense or not? But it's got me thinking my pump is the problem.

What do you think? Also, do you think this is a coincidence that this happened about a month after I installed the ATC last year, or could it be related?

thanks,Mike
 
Hi Mike,

I think it is a coincidence, the ATC cannot "hurt" the pump, it really simply acts like another switch as far as the pump is concerned.

Did you check both ends of the black ground wire at the pump? And does the plug on the pump harness show any signs of corrosion?

It may be time for a new pump, it's pretty rare but they can fail in the "pump forward" mode and only run in "reverse". The click you hear is probably the solenoid valves.

The part number for a new pump is Bennett V351HPU1.

Tom
Bennett Marine
 
Thanks Tom,
No corrosion anywhere that I could find. Everything looked clean. I guess I'm into a new pump. Will the install be plug and play? Any tricks I should know? Also, I'm assuming the pump can be swapped out while the boat is in the water?
thanks again,
Mike
 
Mike,

Yes, plug and play, unless SeaRay used a different type of plug on the harness. They did that on some boats and even butt spliced it on some models, but that is easy to work around.

The pump can be changed in the water.

Fill the reservoir to the full line with any type of Automatic Transmission Fluid (ATF). Run the Tabs up and down 4-5 times, this will automatically purge any air from the system. Then put them fully up and check the fluid level again, top off if needed.

That's it!

Tom
Bennett Marine
 
Just wanted to report back. I replaced the pump....very simple install.... And the tabs work perfectly once again. Guess I was one of the unlucky ones with a pump failure.
 

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