Sounds like a loose or broken connection or a wiring issues. Locate the wiring harness that goes from the fan switch to the fan blower and wiggle it back and forth to recreate the intermittent condition.
Usually, the connector at fan will melt from high amps and create a bad connection creating what you have as a symptom. If that is the case and the connector there is somewhat melted and loose, suspect a bad blower motor drawing high amps. If the connection is good, hook up a voltmeter in the ohm position and do the wiggle test. If that proves to be ok, then suspect a bad blower motor.
To do the ohm check, find the ground circuit and then probe any of the power wires that go to the fan, cuz you say it will do it in any fan speed, s not a resistance issue for fan speed or other. Focus on the wiring to motor.
If for some reason I am wrong, it could be a loose connection at the switch location and should be diagnosed the same as I just wrote above.
Since I live in north america, we don't have senada's. So I am a bit iffy on giving you a wiring for a europe or other foreign model. IF YOU WOULD HAVE WROTE SONATA OR SEDONA, i COULD HELP. i DON'T EVEN THINK i EVER HEARD OF A kIA sENADA. So it is either a sedona, or a sorento.
Oops, hit caps lock and to lazy to correct. Yeah, I don't think a senada exits. So I will provide a wiring for a sedona hoping you just spelt that wrong.
Actually, f this, nothing in my database resembles a 2.0l sedona, sonata. Only 2.0l I a finding is is a spectra car sportage SUV 2wd or 4wd.
Yeah, to many variables to make me post a wiring which may resemble what you ask for. I can find nothing for a Kia senada with a 2.0l in it. SO wiring will be vastly different as the ones I have are more sophisticated than those cheap french models. I don't even know if this one has auto HVAC or manual. Mosfets may come into to play here, but again, I am frustrated because as usual, the foreign market has kept me out of the loop by continuing to not provide us here in the north american continent with proper wiring for ALL FU$%ING models on this planet.
I wonder how the french technicians in france would behave when faced with a fancy caddilac from canada or USA with some HVAC issues and no specs or wiring to go on.
So there goes my rant on open trade, free trade, new world order, open borders and free access to information on a planetary scale and all that shyte. I think I will now go drink beer and have sex with my greek GF and forget how my country just got f#cked by france on that Airbus deal by the all mighty trump giving us a grand a$$ f'ing via boeing.
Neighbors? F trump and the puppeteers that pull his strings. Cuz of this admistraion, france now has 51% share of a quebec company whilst this admin is trying to say it is maintaining an open relationship on trade with canada.