Whenever I turn on the heater on my 2016 Hyundai Sonata and use instrument panel vents and floor vents, there is a squeaking noise coming out. The noise sounds like chipmunks or birds.
However, when I use defrost vents (both rear and front) there is no noise. What could be the issue? Are all vents using the same blower motor? Or are there different blowers for defrost and front and floor vents? Thanks!