2013 Hyundai Santa Fe Sport - AC issues

On a hot weather car trip early of summer 2019, the A/C in my 2013 Santa Fe was turned on to Max and the blower to Max. Shortly afterwards (3/4 hour) the blower power diminished greatly and the cool air volume coming into the cabin also diminished greatly. There was not nearly enough cooling to satisfy us. The heat outside, while hot, wasn’t extreme.
I tried every which troubleshooting approach to fix the problem; including adjusting both blower and air temp settings, for dual (driver and passenger) sides. I could not fix the problem. If I left the A/C off for 20 minutes, the cooling and blowing power was restored, but only for another 30mins or so.

I am a retired engineer and used to work on my car maintenance/mechanics, in the days when cars were much simpler. I could tell that the cooling coils were not damage; later verification and attempts too replenish the condensor did not reveal any damage there. Hence my next best guess that some ‘device’ that controls the air volume via the air outlets in the cabin, was incorrectly closing the outlet flaps. The blower sounded like it was still working hard behind the outlets, but trap doors there appeared closed.

I just discovered a TSB document that was released by Hyundai in 2013 Nov. I believe it may be the solution needed for this problem. I certainly do not fee that it is major, nor do I wish to have the dealer mislead me down the wrong path to an expensive fix, if this blower PWM module replacement works. I will investigate further but anyone who knows if it is the correct fix, please let me know.

Sounds like the evaporator is icing up.

Does the drain on your A/C system leave puddles of water under the car when you shut off the car.

Could just be a plugged drain and the moisture is freezing on the evaporator stopping air flow.


+1. A bad expansion valve can cause a freeze up also.

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it could be a bad actuator motor that controls the blend door from opening and closing.

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I think it very likely your evaporator was freezing over and blocking the airflow. This can be caused by a number of things. Take it into an auto A/C specialty shop for a diagnosis.

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Getting puddles on the ground actually, but of course, only when I stop. But it would be hot out when the problem occurs, hence ice could possibly melt off pretty quickly. This may suggest that coil is not freezing up? But I am still checking this out. I won’t take the car to the dealer, for the usual expensive runaround, but rather to a good A/C specialist and I’ll make suggestions.

This is the wrong approach. Let them diagnose the problem. If you suggest anything and that’s not the problem the outcome is on you. If they diagnose something and they are wrong it’s on them.


Thanks, and I’ll try not to volunteer much the the A/C specialist (which I yet need to find an honest one ). However, if I say nothing they may go through every conceivable troubleshooting procedure, at my cost, only to possibly come up with an answer among those discussed above, but many not. I think there are good ideas by friendly folks above; thank you all and I’ll write back when I get the problem fixed. So far, others with a similar problem could not get the dealer to identify the problem, because it only happens when the air is hot and A/C is working hard. I don’t wish to go through that waste of time either.

There’s a couple reasons not to disclose your diagnostic ideas. One is a less reputable shop will change or repair things you mention just for extra work and you would be none the wiser. Second even an honest mechanic may make the mistake of using your diagnosis as an influence to his diagnosis. All a mechanic needs is the symptoms in detail. Let him use his experience and tools to make the proper diagnosis. Good luck.


If it’s dripping water from the evaporator drain tube while the air volume is decreased then it sounds like a blower motor issue.

When it comes to a failing blower motor that can often take out other things such as blower resistors and blower modules.
You might have the current draw of the blower checked.

Are you sure?
When I go to my Primary Care Physician with a medical problem, I always begin by telling her what my diagnosis is—based on the opinions of anonymous internet people with unknown medical credentials. Surely, automotive diagnoses should be done in the same manner.


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Fortunately your primary care physician doesn’t make that mistake. But some less experienced mechanics do make that mistake. I remember getting people’s diagnosis and that was the first thing I checked. Once you’ve learned to diagnose with symptoms first, it can help avoid wasting time on rabbit trails.

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