Side power Hydraulic Bow and stern thrusters run away problem

[Johnrgould]

It has happen a few times now. The last time we were docking and the bow thruster went full power to Starboard with out any input. Luckily the previous owner installed a kill switch right next to thruster controls so when this happens I can shut down right away. About a month ago docking at another marina it did the same thing and I had to kill it. Another time it did it in the locks and slammed us against the wall of the lock. Right after I purchased boat and had it happen in the locks and I replaced the bow thruster joystick but the problem has persisted. Most of the time it works wonderful and is a amazing tool. Just can never trust it. I talked to previous owner and he said it happen to him also and that is why he had a kill switch installed. He had people in Seattle look at it and could not find anything wrong with it. We are 300 miles up the Columbia River and we do not have many specialized mechanics around here and I was just wondering if anyone on here had any info on this kind of problem. Thank you ahead of time.

 

[Comodave]

I would suspect a bad solenoid or a loose connection on the solenoid. Maybe a problem with the solenoid activating on its own. Check all the connections and maybe replace the applicable solenoid.

 

[luna]

Does the ghost who operates your bow thruster at the most inopportune times always thrust the boat to Starboard or is Port also used on occasion?

 

[Juliet 15]

I had something similar occurring with my side power 15hp bow thruster a few yrs ago. Side power said it was caused by using the thruster when the batteries were low power (another story). The low power battery situation created excessive arcing on the solenoid. Replacing the solenoid (it did indeed have arc-damaged the contacts) fixed it. Not cheap...

 

[Bmarler]

If these are hydraulic with proportional controls I would look at the valve solenoid drivers. I don’t have first hand knowledge about how they engineered their system, but usually there is a joystick control sending a signal to the valve controllers. The valve controllers send either a current or voltage signal to the coil to tell it how far to open. If the controller has a fault on the input side of the board unpredictable results follow.

 

[twistedtree]

First, just to confirm, these are Sidepower brand, but hydraulic? I have always thought of sidepower as making electric thrusters, not hydraulic thrusters, so want to be certain about the equipment we are talking about.

Do they turn on when not commanded to do so? Do they not turn off when commanded to do so? Do both things happen? Does it matter which control station you are using, if you have more than one? Is any part of the control system for the thrusters wireless, or is it all wired?

 

[rgano]

Any luck on fixing this issue?

 

[Johnrgould]

Hi.
Sorry it has been so long for a reply. Yes. They are hydraulic. Bow and stern. The hydraulic system says sidepower. The joysticks on flybridge are donfoss. They are variable speed. Seems to only happen when it thrust to starboard at full power. So I have not been using it at full power and I have not had any runaways. We are doing the light parade in Tri cities this weekend and we will see if it happens again. I am looking into replacing solenoids and valving. I have no experience in hydraulic so I am getting someone to look at it in the next month or so. Thank you for all the input.

 

[Bmarler]

can you give a more accurate description of the failure?
In the original post, you say it goes to full power without any input. This describes a control (input side) problem.
If it remains at full output after releasing the control it could be a sticking valve spool.
A little more information could help the troubleshooting process.

 

[Johnrgould]

Sorry for incomplete descriptions. It doesn't happen very often and since I have started this thread it only has happen once. When it happens it is terrifying and I have a switch that kills the whole system. The thrusters are very powerful and will slam you against the wall. So the last time it did it I mimic it by going full power to move it starboard and it stuck on full power. I killed it and reset it and it always works fine until the next episode. It always happens in the worst situations of coarse. I believe it has to be in the valving or solenoid so I am planning to replace.

 

[Bmarler]

If it’s happening after moving it to full power and releasing, the spool is likely sticking. It would be best to put a meter on the coil wires to verify the current is stopped when the event happens. It’s really the only way to be sure that the controller is doing what it’s supposed to be doing.
That said, It seems very likely that it’s a sticky valve. It would be good to change the filter at the same time you change the valve, just in case there’s some debris in the oil. The filters are usually on the return to tank.
Many times you can just buy the valve body without the coil. That’s the route to go. A bad coil won’t activate a valve, it’s the opposite. A bad coil will not operate the valve, or won’t bring it in fully.