Aft stern thurster

[rsarnott]

I am a new owner of a Cutwater 28. Bringing it home for the first time the thursters worked fine but then quit. When the aft ones when activated sound like there is power to the motor. (there is a clicking noise) A friend who has a C 28 thinks is is a broken sheer pin. Thanks for any help.

 

[Bruce Moore]

Bumping post delayed in moderation queue.

 

[batate]

The imtra customer support is great.

I called with a similar problem: used Ranger Tug 29S. Stern thruster was working intermittently. I was getting 12 v and sometimes it would fire, but other times it would click and eventually it just clicked. They asked me about the voltage drop and had me try to fire the thruster by connecting various wires in the pigtail. They determined it was probably a thruster motor that had seen some water intrusion and that's exactly what it was. When I pulled the motor it was pretty rusted out inside. I replaced it and it has worked flawlessly since.

 

[knotflying]

There are several issues that can cause this symptom. There is a troubleshooting procedure that you can get on line from Imtra. I suggest that you go through the process before replacing the motor.

 

[Ralf H]

Hi rsarnott,

You may be at a point where bench testing is required. If you do the testing as knotflying recommended and don't reach any conclusions, you will need to remove the thruster and take it to an Imtra approved repair shop (in order to claim warranty if applicable). If the thruster is already out of warranty, then you can take the motor to pretty much any competent shop that performs starter motor repairs. These motors are very simple and very similar to automotive starter motors. Any competent shop should be able to help you. Hope this helps.

Cheers,

Ralf

 

[batate]

Pulled thruster and noticed signs of water intrusion. At that point, it's cheaper to replace the whole thruster. We replaced it. The pigtail of the 2014 model doesn't fit. Rather than just replacing the head of the pigtail, we simply ran the new cable, which was pretty easy after we pulled the fridge.

Now it all works perfectly. Thanks for all of the contributions here.

 

[praymond]

So my question is, how is it that so many stern thrusters are getting water intrusion? My RT27 inboard had same issue. Thruster was acting intermittingly and when removed, "rust from water intrusion" according to side power. I see this over and over on the forum. Any one have an idea on why?
Dean and Patti

 

[Red Raven]

So my question is, how is it that so many stern thrusters are getting water intrusion? My RT27 inboard had same issue. Thruster was acting intermittingly and when removed, "rust from water intrusion" according to side power. I see this over and over on the forum. Any one have an idea on why?
Dean and Patti

A little speculation here. There is a limber/weep hole into the bilge from the space below the thruster. If that hole is plugged the space below the thruster can fill up with rain water (or sea water if there is a leak in that area 😱 ). Even when the limber/weep hole is clear there typically remains about one inch of water due to the level of the hole. While this is not enough to reach the thruster motor I do soak it up with a rag or sponge periodically as it does create a moist environment. I have fortunately not had any water intrusion into the thruster motor (yet! :shock: ).

Curt

 

[knotflying]

I would go with Curt's explanation. I kept my limber holes cleared and never had an issue. When I had to service my unit with a new relay, the inside was pristine. The rear thrusters have an explosion proof cover, not because of explosion, but because of the water.