The control panel just provides a couple of contact closures. Functionally
it is an SPDT switch although it has On and Off buttons and a power
indicator LED as well. I'm going to try and tear into it this weekend and
see if I can figure out the problem. When I press the port thrust button I
can hear a relay pick inside the panel, but no activity at the thruster.

Doug

wrote in message
oups.com...
Sounds like you've got a series wound motor with separate terminals for
the field and armature. If my memory is correct the polarity of the
armature winding gets reversed to change rotation.

It looks like your switching modules are working OK which will save you
some money. Otherwise I'd suggest an anchor windlass controller such
as an IMTRA. They occassionally show up on EBAY at halfway reasonable
prices. Be sure you get one designed for a series wound (4 terminal)
motor.