1991 240 overdrive issue

Starting sometime today, my automatic 1991 240 sedan is blowing out
fuse 11. I never had a problem before. Okay, let's assume it is due
to a bare wire on the rear defrost. But where are the wires that lead
to it? And otherwise am I looking at a wire(s) around the transmission
from underneath of the car? Could it posssibly an internally shorted
relay?

 

On my '91 240, the wire running from automatic gear shift knob down to the
overdrive solenoid was not very secure along the top of the transmission
housing, just under the interior console. Over the years, the wire flapped
around a lot, constantly rubbing off the wire insulation where it hit the
tran housing, grounding out on the bell housing. I believe this was
somewhat common. I cut out the worn section of wire, spliced in a section
of new wire and insulated the splice, then wrapped the the run of wiring
inside one of those handy protective rubber-plastic sleeves from Autopro to
make sure it didn't happen again.