BT100 bow thruster - has got ms stumped

[Pat Miller]

Sailing mates - this has got me a little perplexed. Please forgive the saga read. The thruster was originally installed in 2010.

• The BT100 bow thruster alarm in the joystick unit sounded continuously even though it worked fine.
• Joystick assembly and control box was removed and tested. Control box faulty and replaced March 11
• New control box + joystick connected without the diodes. Bow thruster worked.
• Diodes connected but the wrong way around - the diagram on the instructions was difficult to read and upside down. Bow thruster didn't work.
• New control box installed March 18 with diodes the correct way around.
• Bow thruster didn't work.
• Diodes removed. New control box + joystick connected, bow thruster still didn't work. But the fuse was blown (see next 2 steps)
  
• Bench tested new joystick and existing control box. Both worked fine.
• Replaced 5amp fuse that had blown (presumably because of the reversal of the diodes), power to the connection of the control box 13.5v. Plugged it in with joystick, still didn't work.

Could reversing the diodes have done some sort of arcane damage I don't know about? I'm totally stuffed on this one - there's power to the working (bench tested) control box connector on the unit. The joystick is new. The thing doesn't even turn on, let alone beep or show any signs of life.

Here's the link to the manual if any of you out there are so inclined. http://www.belship.nl/belship/manual...le_20BT100.pdf

Thanks in advance - all advice gratefully received.
.

[unclemack]

Had a look at the manual, saw no sign of a diode.

The manual isn't that good though...

[SteveSails]

No diodes shown on wiring diagram. The only place that I can see for external diodes would be across the solenoid coil terminals, the blue/black, white/black wires. These diodes would prevent arcing off the control switch contacts when the switch (joystick) is turned off. Correct polarity would be the diode's cathode to the white or blue wire and anode to the black. Cathode terminal is usually marked by a band around the body of the diode. Reversing the diode would cause full current to flow through the diode blowing the 5 amp fuse and a diode.

Divide and conquer is the strategy now, eliminate the controller and cable first by disconnecting the control cable.
Is the motor/solenoid unit wired as shown in the diagram?
Is the main fuse OK and switch on?
Is there voltage to the motor?
If so connect a jumper from the blue wire in connector 8 to the black(-) wire. Solenoid should click and the motor should run. Repeat for the white wire.

If that worked then the problem is in the control cable or joystick.
Are you sure the new 5A fuse is OK?
Do you have the optional delay timer? Bypass it.
Any sign of burns or damage in connector 8,9? Fix it
Is there voltage at the control (joystick) box? No, recheck 5A fuse
If you have voltage then its possible the control box was damaged when the 5 amp fuse blew. There may also be a fuse in the control box not shown in the manual. As a previous post said the manual is not that great.

Hope that helps, let us know what you found.

[Pat Miller]

Many thanks Steve (and Uncle Mack)

I'll have a shot at working my way through your suggestions.

P

[Pat Miller]

Hi Steve

Many thanks for your advice. It was utterly confounding but the talented Kevin at Twin Disc, the distributors in Brisbane, worked out the problem was in the four pin plug and sure enough, one of its components was bent open and subsequently recessed into the plastic plug giving an incompetent connection. So after immense amounts of farting around and swearing it is fixed.

Thank you hugely for your advice - it gave me the confidence to rip into the little bugger. Now I reckon I have a really good idea of how the bow thruster works, can dismantle / troubleshoot it (I got lots of practice at that!!) and have an intimate knowledge of the bin locker under the forward bunk.

I'm a newcomer to this forum and am mightily impressed by the calibre and generosity of people like you.

Thanks again

P