Hi everybody. I was wondering if other people were experiencing this. My 2013 has 250 miles on it. Starting to get cool here in R.I. Have had heat on before but the other day windshield fogged up turned knob to windshield defrost and the car started to make a humming noise. Turned to floor vents noise went away turned to windshield vents noise starts again for about a minute then stops then cones on again back and forth. Well it turns out this car has 2 electric fans for radiator and turning knob to windshield vents causes then to come on and go off. The favs are for cooling so it does not make sense why the windshield vent selection would cause then to cone on. So I was wondering if other peoples Fit's were doing it as well. Lift the hood with heat on and vents to floor fans not turning, then switch to windshield defroster they both come on like clock work.

Thanks.

 

Defrost setting also turns on the A/C pump so that the condenser can dry the air being circulated through the system. When defrosting the windshield you usually also have the temp. knob turned to a warm setting so you don't feel the A/C blowing cold air. It is the same with all Fits and has been discussed on the forums extensively.

 

Thanks for getting back to me Triskelion. So, what you are saying is that the AC turns on and that causes the radiator fans to turn on. Because with hood open the fans are not on then when switching to defrost setting they both start up turn to floor vent the fans kick off.

 

Yes the A/C COMPRESSOR and A/C fans are turned on when you go to defrost position it helps remove moisture from the interior.