All fan belts are not created equal.
I got the new motor all ready to go on the new swamp cooler, tightened up the fan belt and plopped down on the couch to enjoy the cool.
Lasted about 45 minutes, when it just stopped. I checked the breaker switch, it was fine as evidenced by the water pump still pumping water. I went up top and realized the motor had overheated, it was quite hot.
So I loosened the fan belt, a lot looser than you would ever want your car’s fan belt. Almost an inch and a half of play in the belt. That would squeal like hell on your car.
I had to wait a bit for the motor to cool off, but it’s been running for several hours now, and as you can see from the temperature gauges, it’s working quite well.