The AC blower fan may not be working in auto mode due to a malfunction in the fan motor, a faulty thermostat, a blown fuse, or a problem with the automatic climate control system. It is recommended to have a professional technician diagnose and repair the issue.
If the heater fan works on all speeds, then the blower motor, blower fuse, blower relay, and blower motor resistor pack are all good. If the fan runs but nothing comes out of the vents, you have a 'mode door' issue (which might include a bad control head).
the blower fan resistor has gone bad.
the blower fan is not working in my turck how do i fix it
The blower motor speed resistor is burned out. The part is available from your local auto parts store.
Check the fuse and relay first. Then check the blower resister, then the blower motor itself. One of these is probably the cause of the failure.
Defective blower motor or blower motor resistor pack.
I had a similar problem when one of the speeds on my fan control stopped working. I had to replace the blower motor resistor. It was about $10 at the local auto shop and took about ~45mins to get it in. You could also look at the blower motor it could be blown.
Bad fan switch Bad fuse Bad resistor pack on blower motor Bad blower motor
I just had to replace the fan motor in one. It shorted out.
the blower fan rheostat usually located in blower box is like a resistor that draws energy from the blower fan supply to slow it down and there is a high speed fan relay for the fastest speed. So your rheostat is not working
Your AC fan is not working on the maximum setting because you have a bad blower motor resistor. This is located under the dash or next to the blower motor.
CAUTION!!! This may be a problem with the alternator and the charging. Blower fan will stop working if alternator is not charging. You may also see the battery light and brake light staying on as well! Advance Auto Parts or Auto-zone can test your alternator/battery.