Trim tab not working?

[ProfitOfDoom]

I believe I have a bennet unit and this is in a 1987 268 da.
Im pretty sure the last time I was out last season I thought they wern't working and today I got it fired up getting ready for another season! But I confimed they do not work.
I looked at the switch the ground was kind of corroded so I peeled back some insulator to clean wire at the switch and that still didnt do the trick.

I can see my amp gauge jump around when I toggle the switch but I hear nothing at the motor. Im guessing there is a fuse between the switch and the pump motor but they have everything crammed way back in there and tied to the wall,it will take some time to track it down,Im hoping thats what it is and dont need to buy a new unit?
I just figure I'd ask to see if anyone had any ideas,or maybe had similar problems and had a cure they could share with me? Thanks!

 

[Larry&Leisa]

Check the Bennett web site.. They have a pretty good troubleshooting guide. Their customer service is quite good too. There have been a few threads on this so a search will yield some results too.

 

[Tabman]

Profit,

Here is a link to a video that gives a system overview and Basic Troubleshooting, http://www.bennetttrimtabs.com/videoplayer.php?vID=10

And here is a link for No Pump Noise Troubleshooting, http://www.bennetttrimtabs.com/videoplayer.php?vID=13

On an older system the first thing I always check is both ends of the black ground wire at the pump to make sure they are clean. Also clean any connections where the wire harness plugs into the pump. If the fuse was blown your ammeter would not move when the switch was operated so I doubt that is the problem.

Below you will find troubleshooting you can print and take to the boat. Take a look at steps 3 and 6.

Once you get a chance to look it over let me know what you find and I will be delighted to help,

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).

 

[ProfitOfDoom]

Thanks so much for the help,Im not sure what it was but I checked all wires and grounds and made sure they were clean and just took some scotch brite and ran over all the connectors I was able to see and when I was done I had power!
So rather it was the ground,"I suspect the ground as it looked the worst of the bunch" But it appears to be working fine,I wish all products had service and willing to help like you guys. I wouldnt hesitate to buy this product again for the future needs. A+

 

[Tabman]

ProfitOfDoom,

That's great! I am delighted the system is working and we were able to help.

Tom McGow
Bennett Marine