Driver's side heat only hot, passenger side seems ok

[turboAWD]

Seemed to start today on the way home from work: heat setting seems to not work on driver's side, but definitely works on passenger side to go up / down 20+ degrees. Driver's side seems stuck at full 100% heat.

Passenger side wasn't getting super cold, but that may be because it was mixing with some hot air from driver's side. Rear vent got reasonably cold.

Are these vent flaps all controlled by electric motors? Fuse possibly blown? Anyone had anything like this?

 

[Ah GetFd]

Are you talking about just a heat problem? Are you talking about just a cooling problem? Are you talking about a heat and a cooling problem?

You jump from having 100% heat on the driver's side to having super cold on the passenger side.....

If it is a low refrigerant (gas) problem you are going to get non cooled air one side, and cool the other as there is insufficient gas in the system.

If it is a vent problem that you think is allowing heated air in where you don't want it then it is something entirely different.

There is a procedure I believe to cycle the vents and factory set them back. I have seen it somewhere.

You can start here and work your way through.

Kia Stinger - Heater & A/C Control Unit (DATC) - Controller

Kia Stinger - Controller - Heating, Ventilation And Air Conditioning

Kia Stinger CK 2018-2025 Service Manual

 

[turboAWD]

Thanks for the links - I only have the pdf version from long ago.

The problem was heat controls were working (full range from cold to hot) on passenger / rear, but not for driver - driver was stuck at 100% heat (quite hot) no matter the actual temp setting on the temp knob. However, driver's display was showing changing temperature. And it was way hotter than ambient, so clearly the flap was stuck "full open" (or whatever type of control it actually is).

Today, it's acting as if nothing ever happened - both sides have full range of temperature control again.

How would low refrigerant cause one side cold, one side hot? There aren't separate AC units for the two sides, as far as I know. And even then, "cold" should be somewhat close to ambient, not "hot as it can possibly get", right? Edit: ambient is ~45-60F (7-15C). Driver's side temp was was hotter than that.

 

[Ah GetFd]

see reply

 

[Ah GetFd]

Thanks for the links - I only have the pdf version from long ago.

The problem was heat controls were working (full range from cold to hot) on passenger / rear, but not for driver - driver was stuck at 100% heat (quite hot) no matter the actual temp setting on the temp knob. However, driver's display was showing changing temperature. And it was way hotter than ambient, so clearly the flap was stuck "full open" (or whatever type of control it actually is).

Today, it's acting as if nothing ever happened - both sides have full range of temperature control again.

How would low refrigerant cause one side cold, one side hot? There aren't separate AC units for the two sides, as far as I know. And even then, "cold" should be somewhat close to ambient, not "hot as it can possibly get", right? Edit: ambient is ~45-60F (7-15C). Driver's side temp was was hotter than that.

This a common symptom in virtually all car airconditioning systems when there is low refrigerant. One side blows cold the other side is warm. Probably due to how the condenser is positioned inside the dash. It probably gets cold in one section only and air passing across it goes out the first vent which is reasonably cold whilst the remaining air that passes across the condenser part that is not cold and passes into the second vent relatively warm.

Also, another situation is if the thermostat is faulty. The aircon will run all the time and ice up under the dash which restricts airflow, so rather than being cold-er it is actually warm -er that side where it is blocked by ice. The tell tale sign is a big puddle of water under the car after you turn it off for a half hour. This could explain why your aircon works on shorter drives but doesn't work well on longer drives.