Ac Blower Fan Not Working In Auto Mode

Test to make sure you are getting 24 to 28 volts ac between the g green and c com terminals on you fan center or control board if you aren t getting 24 volts between g and c then you might have a thermostat problem a thermostat.

Ac blower fan not working in auto mode.

My home ac fan blower does not work in auto mode but it does work when i slide the switch to on. If i turn the system on with the fan on auto the fan will never spin up but the a c does make noise like it s doing something sorry for the laymans jargon but i m not the most experienced with hvac stuff also if i try to switch the fan to on after the a c is already switched to on the fan still does not turn on. However if the system is in cool mode and the fan is set to auto nothing happens. Wiggled green wire where it connects in the air handler and auto fan mode seems to be working now.

I swapped out the circuit board but the same problem persist. Is the thermostat not working correctly or something in the ac unit causing it to do this. If i leave the fan on then the ac works fine cooling correctly. If i have problems still i will return.

The heat and fan worked well over winter. The inside fan doesn t run when in auto mode. The ac compressor outside works fine. So for some reason the auto fan mode does not work.

Maybe i was just impatient before when i was testing it. I can also turn the fan mode to on and the fan will run. As a side note i was a bit worried of fire if the blower did not turn on. I read somewhere the blower had a 4 min count down before turning on again.

The outside unit keeps running when cool on.