Definitely check the switch as PB says. Also could be stuck. A non-turning motor like that is close to a dead short. Of three TR6s I've had that had been off the road for many years, two had stuck fan motors. I had to pull the heater;remove the glove box and pass-side heater ducting, and you can struggle it out the passenger side with moderate contortions and cussing.
Jeff
74.5 & 75 TR6