One motor I had was squealing and I sprayed some wd40 or similar on the motor bearings. It had set for a while and this got it going. Another time on another AC the motor wouldn’t spin. Had an AC guy look at it and he replaced some bushings on the motor mounts. They had let the motor settle down and it wouldn’t spin. If I remember correctly the bushings were about $10. Plus the service call of course. If you could get the fan to run long enough you could tell if it is getting cold, especially with top cover off you could see if lines are getting cold or not