Stern thruster is coming on for no reason.

[bbrh842]

The stern thruster is coming on for no reason. The marina just called and said the stern thruster on my R-25 is running. I left the marina 45 minutes ago. Why would the stern thruster decide to come on, when there is nobody on the boat to engage it ???????

 

[wefings]

Moisture in the controls will do it . I have had it happen . We recommend turning the main Thruster Switch off when you are away from the vessel.
Marc

 

[bbrh842]

Wow Marc! Who whould think, that someone would make something for a boat, that could cause the boat to crash, if it got damp!! I am glad it did not come on for no reason, while I was docking the boat.

 

[JerryE]

This may be a good reason why the thrusters on the later boats were "sealed"; to protect the electrical connections.

 

[doke01]

Is your stern thruster the sealed version? Some of the earlier, 2007 stern thrusters were not the sealed version and there is a bilge drain right next to it that would get it wet and ultimately cause it to fail. Mine didn't start running, but it did overheat ( I mean so hot you couldn't touch it and it was smoking) and it killed the thruster battery. I had to replace it with a sealed unit (that was definitely no fun at all but I posted the process on tug nuts you can search for). A sealed thruster looks something like this: http://www.side-power.com/public/templates/default.php?id=139
An unsealed thruster looks something like this:
http://www.side-power.com/public/templates/default.php?id=73

In order to see it you have to open the door on the deck underneath the rear cockpit seat, get your head inside, use a flashlight, and look down and to the right.

If you have the unsealed version I highly recommend you replace it because, if it is the cause of the problem, it will fail again. Andrew can let you know who to get in touch with at the manufacturer.

 

[doke01]

Here is your answer by the way. You can see my post about replacing the thruster but others had the exact same symptoms that you do so I expect you have an unsealed stern thruster:

http://www.tugnuts.com/viewtopic.php?f=5&t=125

 

[Andrew Custis]

Thanks for everyones insight on this. I also agree that the thruster has seen too much water and most likely caused by a clogged drain. There are drain holes that drain the battery compartment into the thruster compartment and then into the engine compartment. Its a good idea to frequently check the operation of your drains to ensure they are not being clogged by debris. This can still happen with the sealed motor if it sits in water. These units are meant to be in a wet environment but not submersed under water. You can contact Imtra corporation at 508-995-8188 and they should be able to help you in the troubleshooting as well. I frequently use Mark Raeder as my contact. Thank you!

 

[commander bill]

There has been other failures which allways seem to be the rear thruster. My rear thruster motor is currently removed and shipped back to the factory for the same reason. In early November it starting coming on in the middle of the night and causing all sorts of disturbances. I was spending a week or so in the water staying at a wet slip in Florida. I have never previously left any battery switches "ON" when away from the boat but since I was staying onboard I they were "ON". The night-time humidity was about 9999% and condensate was collecting everywhere inside and out. I was operating the AC in daytime and a smaller heater at night to lower the inside humidity. For the next few days everytime I tryed to turn on the thruster switch the thruster would come on and operate. The boat then stayed in dry storage for a while before the motor could be removed (allowing me to use the other thruster and anchor windlass). By then the problem would not repeat. I had no prior flooding of the area where the thruster is located and Andrew confirmed that I have the newer sealed design. After sidepower was called they said the internal ckt board must have become corroded and could only be replaced by them after disassembly. I am disappointed that these expensive motors can fail without any apparent contact with any moisture other than condensate.

 

[Ram]

Has this issue ever been resolved? I am having the same problems with my 2007 R-25. The stern thruster comes on spontaneously when the battery is connected (no contact at the switch panel). I have checked the switch and all of the wiring and it appears to be in the motor housing itself. A local mechanic suggested there might be water sloshing inside the housing that is shorting the solenoid. It sounds like I may not know the answer unless I remove the entire assembly? That's a complicated and expensive operation as has been indicated in other posts. If anybody has a simpler solution to the problem I would love to hear it.

 

[bbrh842]

The issue was resolved by me buying a new motor for about a zillion dollars and then paying another zillion dollars to get a mechanic to install it for me. The old motor had moisture in it and was ruined. My theory, on a cold rainy day, moisture can condense inside the motor and cause a short. The motor is a stone cold lump of metal, and the engine room is full of warm moist air, perfect conditions for moisture to condense on and in the motor. After replacing the motor, I made it a practice to always run the rear thruster for a minute or so after leaving the dock, to warm it up. I also made it a practice to always turn off the thruster battery switch before leaving the boat. By the way, this "Self Starting" problem (That's what Imtra calls it) has been reported even by folks that have the so called "sealed" motor installed on their boat.

 

[Beerthirty]

Guys,
I too have had this problem and fixed it, but I have a problem again. The first time it happened the stern thruster failed after having taken on water through the rudder mount, (don't ask). I pulled the sealed thruster and with the help of Andrew and the guys at Imtrop, tested it and ultimately replaced the solenoid and the power control. I put everything back in and it worked like a champ for about 4 months. My last outing it failed again only this time I hadn't gotten it wet. So far I've been too pissy about it to pull it again and re-test it to find out what's wrong but I guess it probably got some moisture in it. I don't know how. Once you've done this job you will be certain that the drain holes remain open and I've been religious about it. I suppose I'll get out there soon to get it out again but I was hoping someone had a solution to this problem because I don't want to have to do it a third time. It's an extremely uncomfortable job to do and the parts are about $300 to replace. Anyone have any ideas?
Bill

 

[bertnbb]

I have a 2012 Cutwater 26 and the stern thruster came on (and stayed on) while we did donuts in the harbour. I could only stop it by holding the joystick to port (the direction it was pushing the stern). I turned the battery switch off and fished for the day. On return the thrusters worked fine.
Yesterday while drift fishing the stern thruster would come on for a second or two, then stop. By the time we returned to port the stern thruster was dead in the water.
I have emailed the local Ranger/Cutwater support facility and should hear back Monday.
I will update this post as things happen.

 

[walt2]

I have a 2012 R-25 and had the rear thruster replaced under warranty last fall. Same symptoms as you have noted. It will only get worse until replaced. Once it started happening, I always turned the main switch off after leaving the dock, and then only turned it back on just before it was needed. This worked for a while until it came on by itself while trying to dock. After that I unplugged the connector under the rear seat, which diabled the rear thruster, but still allowed operation of the front thruster.
After the new thruster has been installed I check the thruster compartment for water before heading out each time. The drain from this compartment into the bilge is too small and will clog with the smallest debris. Sometimes I can clear it it by spraying from the hose from the engine compartment back to the thruster compartment. Other times use a stiff wire to pass under the foot rest in the engine compartment to reach and clear the drain hole.
In my case there was actally a leak at the thruster mounting bolts and filling up the thruster compartment. I completely dried out the compartment and after about 15 minutes water was starting to pool at the bottom of the thruster compartment.