Hi All, I've got a weird problem that I can't seem to solve.

Last week a fan started running while the vehicle was running and hasn't
stopped since.
The fan noise seems to be coming from the area of the passenger side of the
rear seat.
Checking through Bentley reveals that it may be the aux heater circulation
motor. I unplugged some wires attached to the motor but it still continued
to run. Also couldn't find any wiring diagrams for an 85 Westy in the manual
(91 edition). 
Does anyone have any ideas?
Thanks.....Harry(85 Westy)