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?