Bowthruster not thrusting

Did you check the fuse at the batteries? The batteries will still show good voltage but if the fuse is gone or has bad contact the thruster will not go. 

Did you check the voltage at the batteries when the thruster tries to start. If one or both batteries have failed the voltage will drop  when the thruster tries to start. When the thruster is not trying to start the batteries with no drain can show good voltage especially when they are being charged all the time.  

Check the battery cable connection to the thruster motor - loose? corrosion? 

At least here in the US,  I've had good luck calling QUICKUSA and discussing the problem over the phone.    They talked me thru one issue, which turned out to be a blown fuse, and my initial confusion regarding controller fuses and the actual thruster fuses.   Not sure if you have someone similar to call in Sardenia.

In the meantime a Pro mechanics close to our homeport in Sardinia (http://www.nautitec.net/)   was aboard and measured the currents, concluding that the motor isn't responding. He will take it to his workshop the next days. Although we used it many times sailing from Germany to Greece in two seasons and visiting 120 marinas maneuvering a lot with the bowthruster, I was amazed of this verdict. Four years of use, approx 400 moves and already broken ?? Can't we expect a longer lifetime of these parts? I'll keep you updated.

One of the things I learned early on was to use the thruster in short bursts.   Long runs for the thruster would damage the motor (I was told).    This may be a myth, but I've tried to keep to it.

Not sure if that matters in this case, but thought I would pass it on.    My damage to the thruster was caused by sucking in some line.   Others have told me that long bursts hurts the motor itself.