Blower motor on a/c furnace not coming on

All the motors including the compressor on the outside unit have start/run capacitors. These can fail and when they do, the motors wont start

Will your blower fan kick on in the medium position by chance? Med/ med high..if it is a 4 position switch, does it operate in the number 3 position? If so it is probably your blower motor resistor. If not, I would test the blower motor itself. Since the compressor kicks on when you turn the fan on, I would think the switch is working.

IT SOUNDS LIKE THE FAN CYCLE RELAY OR BOARD IS NOT MAKING THE FAN COME ON WHEN IT SHOULD THE BURNER SHUTS OFF PROBABLY BECAUSE IT REACHES THE HIGH LIMIT.

It shouldn't be too loud. You don't explain where the noise is coming from? The air handler/furnace or the outdoor unit.

The fan runs continously because your condensor is not kicking on and removing the heat. The thermostat needs to come under the set temp. to kick off the fan. If your compressor doesn't run and the fan on the outside unit does run, your compressor has an issue. If nothing runs outside, then your transformer on the inside unit(air handler) has an issue. This could also be a control relay on the condenser or the air handler.

Bad blower motor/capicitor or relay. Check the fuse if it has one.

Check the voltage source for the fan and compressor
Check the start capacitor for the compressor.If its over heating :bad compressor

Likely a bad motor, when this occurs verify the board is sending voltage to the motor.

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The thermostat is the controller.

Sounds like mine did
it was a realy switch