Side-Power Bow Thruster Problem

[Howler]

I have a Side-Power SR80/185T bow thruster on a 34 ft monohull. When I try to retract it, it goes up and down three times, then stays up. The control panel gives the 3 flash yellow and red alarm code. Per the attached alarm table, this means there's an obstruction and after three attempts, the thruster should remain partially open until the obstruction is cleared.

The strange thing is that there is no obstruction. I dived under the boat to look closely. And, the thruster retracts completely, flush with the hull, even though it's complaining of an obstruction.

A few hypotheses:
- We have touched some floating deadwood with the thruster deployed. It was nothing big enough to have damaged the thruster, but maybe it tweaked it just enough to allow it to close with just enough gap that the sensor thinks it's still open.
- The sensor is bad or out of alignment.

If anyone has had a similar issue with a similar thruster, I'd appreciate knowing what you found and how you resolved it.

Thanks!

[ItDepends]

Howler,

I think your problem is pretty simple.

I suspect that the limit switch that tells the controller the thruster is all the way up has either failed or been knocked out of adjustment. Not an unusual problem with these.

The controller turns on the lift motor, and the thruster goes up, and up... until it hits the hull. But as far as the controller knows it is NOT all the way up yet. So it "thinks" obstructed... and cycles.

I haven't worked on any as small as yours likely is, but on most sidethruster units the limit switches are simple sealed pushbutton switches easily available and replaced.

Good luck!

[Howler]

Originally Posted by ItDepends

Howler,

I think your problem is pretty simple.

I suspect that the limit switch that tells the controller the thruster is all the way up has either failed or been knocked out of adjustment. Not an unusual problem with these.

The controller turns on the lift motor, and the thruster goes up, and up... until it hits the hull. But as far as the controller knows it is NOT all the way up yet. So it "thinks" obstructed... and cycles.

I haven't worked on any as small as yours likely is, but on most sidethruster units the limit switches are simple sealed pushbutton switches easily available and replaced.

Good luck!

Thanks. That would be consistent with the symptoms. When you say the limit switches are easily available and replaced, is that typically something that can be done from inside the boat, or do you have to haul out to access it?