Anyone know about Vetus bow thrusters?

[Simpo Two]

I asked my boat expert to investigate why the bow thruster is weak and fades away after a few seconds. It's not the battery as the stern thruster is fine.

He writes: 'There is a pair of solenoids mounted to the side of the thruster motor. One gets warm, the other one doesn’t. That doesn’t seem right to me. It might be a case of removing the whole motor and getting everything reconditioned. I spoke to Vetus but they couldn’t offer any real help.'

Thoughts welcome please.

[Krikkit]

Solenoid heating is usually a sign of internal issues - if you can get to it, and get a replacement, that'd be my first port of call.

They should get warm naturally under high-current, but one getting hot compared to the other is a sign of issues.

[Jaguar steve]

You haven't got something like a piece of rope or wodge of weed in the thruster tube that winds up and slows it down after a few seconds?

[swanny71]

As above, check prop blades/tunnel for damage and fouling.

A few thoughts from experience with bow thrusters in general, though I’ve never had one battery powered.

Check all electrical connections, especially on the high current cables (remove, clean & re-tighten).

Did your expert thrust in both directions when testing?
I’d assume that since there are two solenoids, one operates if thrusting to port, the other to stbd. One solenoid might be warmer than the other simply because thrust was applied in only one direction.

If the stern thruster is same make/model and your expert is willing then try swapping the suspect solenoids between the two?

Can the thruster be operated from more than one helm station? Test from all stations and if possible locally at the motor - might be a controls problem. Joysticks, especially those outside, commonly cause issues.

And then get into motor winding tests…

Edited by swanny71 on Thursday 9th September 15:48

[Simpo Two]

Thanks for the ideas - I've passed them on and hopefully we can narrow it down.

The bow thruster has been weak for a year or more. The boat was last out of the water in about April and it was clear then, so I don't think it's a blockage.

[Audis5b9]

I assume both thrusters are powered by the same battery?

Is the bow thruster further from the battery than the stern thruster is?

I'm no good with electrics, but perhaps the wiring to the bow isn't sufficient to keep up with the demand?

[Simpo Two]

Audis5b9 said:

I assume both thrusters are powered by the same battery?

Is the bow thruster further from the battery than the stern thruster is?

I'm no good with electrics, but perhaps the wiring to the bow isn't sufficient to keep up with the demand?

From the same set of batteries, yes. The bow thruster is about 22' from them, but I'm assured the cable is more than adequate for the current.

[hidetheelephants]

Simpo Two said:

Audis5b9 said:

I assume both thrusters are powered by the same battery?

Is the bow thruster further from the battery than the stern thruster is?

I'm no good with electrics, but perhaps the wiring to the bow isn't sufficient to keep up with the demand?

From the same set of batteries, yes. The bow thruster is about 22' from them, but I'm assured the cable is more than adequate for the current.

If you connect a freshly charged battery and a set of jumpleads to it, does it still exhibit the same symptoms?

[Simpo Two]

hidetheelephants said:

If you connect a freshly charged battery and a set of jumpleads to it, does it still exhibit the same symptoms?

Not having a freshly charged battery, or even a flat one, lying about, I can't tell you...

[hidetheelephants]

Given the number of components, connections and electric string between the egg whisk and the battery, starting at the front and confirming the egg whisk is working would be the first thing to do.

[Steve_D]

hidetheelephants said:

Given the number of components, connections and electric string between the egg whisk and the battery, starting at the front and confirming the egg whisk is working would be the first thing to do.

Which begs the question why the 'boat expert' didn't do the first test I would do and that is put a good battery across the motor leads and eliminate anything else going on between helm and thruster.

Steve (not a boat expert)

[Simpo Two]

Steve_D said:

Which begs the question why the 'boat expert' didn't do the first test I would do and that is put a good battery across the motor leads and eliminate anything else going on between helm and thruster.

Would that help determine why one solenoid gets warm?

[Steve_D]

Simpo Two said:

Steve_D said:

Which begs the question why the 'boat expert' didn't do the first test I would do and that is put a good battery across the motor leads and eliminate anything else going on between helm and thruster.

Would that help determine why one solenoid gets warm?

What it will do for starters is determine if the thruster motor (and its blades etc) are running well i.e. not lazy/sluggish as you originally reported.
If it is sluggish then you can discount anything else in the power supply/controls system and just concentrate on the thruster itself which will most likely need to come out.

If the thruster is a happy bunny with a direct power feed then your problems are elsewhere in the boat.
One relay being hot is not in itself a problem as we do not know how it is wired and may be normal.

If you do test the thruster with a battery test run it in both directions.

Steve