Here we go again - more trouble

Something bad has happened and I can't figure out what. When the
Gecko blew I found a loose wire. I replaced the wires and checked
all connections. Checked motor to see no connection between
windings or internal shorts. New fuse then blows when powered up.
Now with the new Gecko in place, and all the wires checked, there is
a full 75 volts across the fuse holder (fuse removed) leading from
the power supply to the drive while no voltage across the good
fuses. The only thing I can figure is that the motor has been
damaged and there is a short. There is continuity between the phase
a and b and between c and d (as there should be) but no connection
between a and c or a and d etc that would suggest a short.

I am not sure what to check at this point. When I put in the fuse
it blows. Not sure if the new Gecko is dead or not. Can't imagine
that the motor is bad though.

thanks
Keith Clark