Stern thruster stopped workin.

Just Limin'

Well-known member
Joined
Dec 7, 2011
Messages
154
Fluid Motion Model
C-26
Hull Identification Number
2517
Vessel Name
Just Limin'
My 25 SC was just trailered to Florida. When we put it in the water, the stern thruster would not work. Strange. Thoughts?

Bill
Punta Gorda, Florida
 
Bill:

Do you hear any noise at all? If so then it could be a broken sheer pin that will need to be replaced. If no noise you might check your fuse panel for a blown fuse. Let us know what you find.

Jim F
 
Just Limin'":o9sgdh2o said:
My 25 SC was just trailered to Florida. When we put it in the water, the stern thruster would not work. Strange. Thoughts?

Bill
Punta Gorda, Florida

Bill,

When you activate the thruster joy stick, do you hear the thruster motor whirring? If so, is it a high pitched whine rather than the normal lower pitch of the working bow thruster? If so, you likely have a broken shear pin.

If there is no thruster motor noise at all, then you likely don't have a broken shear pin. In that case, you will need to do some additional troubleshooting. As "Jim F" noted, it might be a blown fuse. There have also been some cases of bad connectors, bad solenoid, or bad controller, some of which are caused by water intrusion into the thruster.

Try this link for info about broken shear pins for bow and stern thrusters:

viewtopic.php?f=5&t=2013&p=14393&hilit=+bow+thruster+picture#p14393

Tell us more about the symptoms - noise, lack of noise, etc - so that we can better determine the cause.
 
Another possibility could be loose wire(s) below the thruster toggle switches.

1) Check for noise pitch... High pitch possible means shear pin issue.

2) No noise might mean fuse blown or loose wiring somewhere.

3) Does the bow thruster work ? If so, this may eliminate loose wiring being the issue.

4) Do the bow and stern thrusters each have their own fuse ? I dunno about this. The fuses are at least 100 amp if I recall.
 
Bow thruster is working. No noise from the stern thruster. Everything worked fine before the boat was hauled, painted and trailered down to Florida by the dealer. Before he left, he checked the fuse and thought it was fine.
 
Could the stern thruster prop have become stuck in too much bottom paint applied to the housing and blown its fuse? BTW, it's 150 amps on my 2013 R-27.
 
Worked intermittently today. Slow to react to joy stick . Worked a few times and the just wouldn't work again.... So, that tells us something?
 
Now it sounds like a joy stick issue to me...like dirty or worn contacts.

T.
 
same things have happened on our stern thruster last year.

ended up having dealer pull the thruster and had it sent back to Imtra under warranty.
 
Can the thruster control unit be "lifted out"?
 
Bill, yes the joystick control unit can be lifted out. Very easy - four screws (one at each corner) on the mounting head which are accessed by lifting the small flap covering them. Remove and unit will lift out. Second, on this site is an excellent troubleshooting guide for thrusters, you can access by opening the link to factory technical bulletins. I had to replace mine several years ago when the boat next to us took a lighting strike. The voltage which jumped to us fried my thruster control head and all of my Garmin nav system.
 
The mechanic tested my joy stick control today. He believes it's fine. He believes water has gotten into the thruster unit in the well where it sits. The water proof unit..... He's going to pull it and open it up. Says it may have to be sent back to the factory.
 
Did you check the contacts in the plug that is in the stern that has the wires coming from the joystick to the thruster. There is a plug connector in the stern. Find it and check it out before you start pulling the thruster out.
 
If there is evidence of water in the rear thruster compartment you probably have a corroded thruster which is not worth fixing (speaking from experience). Likely that there was water in the compartment and going up and down hills while on a trailer enabled water to surround the thruster casing which while well sealed is not "water proof". It might also have rained while underway towing which will put fresh water in compartment if boat is tilted enough. I put large super absorbent diapers in the thruster compartment and every year end I replace. They are always saturated. Where does the water come from? My guess wash downs, heavy rains. I am often in large swells and do not want that water on the thruster. Had to replace the thruster once in non warranty conditions and did it myself and my arms have still not shortened back to their original length. As for the diaper I can't recommend it to others (who knows what is really going on back there) but I will continue to make it part of the yearly maintenance program. Incidentally mine acted the same way before it totally failed.
 
If the 25 installation is like the 27, check the pigtail from the connecting wire that goes to thecontrol. My 27 connection is in a connector that is position on top of the holding tank. The pigtail goes from this connector to the plug in on the back of the thruster. Due to the position of the shelf which the holding tank is on and the position of the plugin on the bach of the thruster, the plug end of the pigtail must be bent at a right angle to get the space needed to align it correctly, small fin on the plug, and pushed into the thruster recepacle. Over time this extreme bend and vibration caused a short in the wire. Imtra proveded a new pigtail and problem solved. But, the shrink wrap on the wire at the plug is long and stiff, requiring again the sharp bend to get the plug in. Imtra indicated that some older pigtails had a shorter shrink wrap area making the bend less extreme, but all the new ones had the longer stiffer end near the plug. Hope this makes sense.
 
The connector that Alibi mentioned is the one I referred to in my post. It has been a problem on other boats.
 
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