New Member
Jul 1, 2021
Buffalo, NY
Boat Info
1996 Sundancer 240
5.7 Mercruiser w/Alpha I
Hi, I just bought a 96 sundancer and the trim tabs won't go down. At first I checked the fuse and that was blown so I changed that. After that the pump ran but had no fluid in it so I filled it and tried again. Still nothing so I crawled in there only to find that the hydraulic line for the port side had fallen off and I was just shooting ATF all over. I fixed the hydraulic line and tried again but still nothing. I now moved on to all of the troubleshooting videos and they have passed all the tests but still don't move! Are the trim tabs just broken? Please help!
Just a thought but are they in the full down or full up position? Are they "stuck" or "Jammed" in the full position and can't move freely? I have had rams get stuck because they were jammed to the extreme and couldn't move.

The manual says;

If HPU runs but the tabs do not move-
inspect for disconnected or corroded red and green valve wire connections at helm control and quick disconnect plug

The following test can be used to help isolate malfunction.

Remove wires from helm control and touch together as follows:
Operation Reaction
Orange(+), blue, red Port trim tab down
Orange(+), blue, green STBD trim tab down
Orange(+), blue, red, green Both tabs down
Orange(+), yellow, red Port tab up
Orange(+), yellow, green STBD tab up
Orange(+), yellow, red, green Both tabs up

If trim tabs function in each of the above combinations, check helm control. If during this test trim tabs continue to malfunction, inspect HPU.
Thank you for responding, I did all the troubleshooting with the wiring and everything worked. I pushed on them and got them to go down and spring back up manually so they don't appear to be stuck?
Time to take the rams apart and clean them. Make sure the fluid is flowing with the rams a part. Just be sure to keep everything extremely clean. Don't even want towel lint stuck to anything when working on any kind of rams.

Or you can call Bennett Customer Service and see what they have to say.
Ok. I called Bennett and they said to check at the pump to make sure there is a steady stream coming out with no air and then do the same at the actuators. If its not that then have to take them apart like you said.
Will having the trim tabs all the way up effect the way the boat rides or will it just be like I don't have them?
It takes a little bit to "bleed" the lines - how long were you holding the "deployed" button?

Yup - you're fine w/o - go boating.
I got them working by pumping them up and down manually and also using the switch. They must have just been stuck and finally jarred loose when I was pumping them with my feet in the water.
Mine are doing the same thing. I can hear the HPU running but either tab moved in either direction.

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