2014 MKZ blower fan going crazy.

Question

I hear a “pop” near the interior fuse panel and then the air turns on and blower fan speed keeps changing speeds out of control. Can’t turn off a/c or control fan speed or turn on Auto a/c control. What could it be? A relay or resistor?

Answer 1

It's possible that there is an issue with the blower motor resistor. The "pop" sound you heard could have been an electrical short caused by a faulty component.

The blower motor resistor is responsible for controlling the speed of the blower motor, and if it fails, the blower motor may get stuck at one speed or keep changing speeds uncontrollably. On the other hand, the blower motor relay controls the power supply to the blower motor, and if it fails, the blower motor may not work at all.

Comments

Thank you, I thought it was a relay or resistor. I needed to know before a take it in and get charged 2-3 hours for diagnosing.