My First Boat Project

Just bought a 2007 290 SLX. I am going to be changing the hydraulic trim tabs to the electric worm drive units from LENCO. I need to run the wiring harnesses from the dash to the transom locations. I've never worked on boats before. I am a carpenter, mechanic and engineer though so.. I am excited and/but nervous too. Not sure if its easy to thread.. if theres a big chase for wiring.. any info you could supply would be GREATLY appreciated!
thanks

Are the current tabs broken?

Generally speaking, the hydraulic tabs are much more reliable than the electric versions. If they're not broken, I would recommend leaving them as is - they are an excellent system. If they are broken, they can be fixed at a MUCH lower price than changing to electric... and they should give you decades of service with no maintenance.

interesting. one does not work. I have been told the opposite by a couple of knowledgeable marine surveyors. I do know that worm drive (positive drive) motors are reliable compared to hydaulics.. any thoughts on the installation / conversion? really interested in snaking the wires... also where to attach the on/off sensor wire.. lastly any thoughts about removing the existing hydraulics if anyone has done this or just abandoned it all..

Greetings and welcome Katemma,

Once you are here for a while you will find there are a couple of guys on the board that you can really put a lot of trust in there opinions. Lazy is one of those guys. It sounds like you have just had a component failure. The time, effort, and money you may need to lay out, might be used better elsewhere? 30 years on my hydraulic tabs and no issues. Just something to think about.

-Mike

OK, well I dont have a schematic of the TT system layout. What are the typical issues/solutions if one of the cylinders isnt working? Are there any maintenance items that I should attend to? Maybe I should just call Bennett marine and speak with them..

Katemma Life said:

OK, well I dont have a schematic of the TT system layout. What are the typical issues/solutions if one of the cylinders isnt working? Are there any maintenance items that I should attend to? Maybe I should just call Bennett marine and speak with them..

Click to expand...

Crazily enough, there is an entire thread for tabs:

http://www.clubsearay.com/index.php?forums/bennett-trim-tabs-vendor-forum.65/

One of the techs was very active in helping everyone out, I'd start there

The Bennett Tech is very active on here. I have never seen a situation where he was unable to find the fix. His name is “Tabman.” I am sure he will respond soon. If not, you might try to PM him.

Bennett

ok thanks to everyone for their replies. I will check into this further. there are so much less moving parts on electric systems but maybe for me, a repair approach is better

I see more issues with the Lenco's (not that they're a bad choice, though) than the Bennett's. Hands down. The Lenco's are an electric motor mounted outside the boat - generally speaking, that's not as good as having a motor mounted INSIDE the boat.

I have never "replaced" a Bennett system with a Lenco, but you will need to look into whether you need to fill holes in the transom, in addition to the wiring and any modifications you'll need to possibly do to the dash for the controls. There are no wire chases - run the wires under the stbd gunwale - may have to remove some panels along the way. If you have looked, you should already see wires going that way.

Can you physically push the trim tab down? Try that (compare to how hard it is to push the good tab down). Are there leaks on the outside or the inside of the transom where the nipple is? It really is a well engineered system that 99% of the time will last many decades with no thought put into it.

Thanks LD

and... what's the fluid level look like with the tabs retracted?

"Tabman" was with Bennett for as long as I have owned a Sea Ray. He is very active here and Bennett in general has the best customer service of any vendor in the entire industry. THat alone is enough reason to not abandon a simple and efficient system.

My boat is used 12 months a year, is a '96 model, the tabs are original to the boat, I have never even had to add hydraulic fluid to the pump and had not had one problem what so ever with the Bennett tabs.

The systerm is modular and you can usually repair anything wrong with them with o-rings, maybe an actuator and the most expensive part is the Hydraulic power unit that costs about $225 including shipping. You will spend a fraction of the cost of Lenco tabs fixing the Bennett tabs abd you will have a far superior system. If you want to improve something, add Bennett's Auto Tab Retractor this winter.....they raise your tabs automatically when you turn off your ignition or accessory power.

This is one of those "Don't fix what ain't broke things"......stay with the Bennett tabs.

If one side is not working, take a look at this video:


Then do step 3 below and let me know what you find.

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).

well I couldnt have asked for any better help than what I've received here. A sincere thank you to all of you folks. I have my direction and will be working on this stuff in a couple of weeks.

one last question - would having wider tabs on the transom be a good idea for better stability? here are some pictures

You really don't have room for wider Tabs to make it worthwhile as the actuator needs to be centered in the Tab side to side.

If you feel the boat needs more lift. You can add DF12 drop fins to the existing Tabs. They capture water pressure normally lost out the sides of the Tabs and channel it aft to increase lift.