Thread: Santa Fe heater issue

Hey team.
Just wondering if there are any mechanics that might be able to assist with their knowledge.

I have a 2012 Hyundai Santa Fe with dual heaters (passenger/driver). The driver side works perfectly, but the passenger only blows cold. It’s the whole left side of the car, when you defog the windscreen there is a line right down the middle. The car still changes between feet/face/windscreen, just blows cold.

My research told me that it is the blend door actuator that is faulty. I bought a new one as that seemed the most likely culprit. I took the dash apart and tested the actuator in place. Frustratingly seems to be doing what it should. It moves up and down as the temperature dial is changed. I have not installed the new one as I want to be able to take it back.

My next thought would be to flush the heater core, but even if that is partially blocked I don’t see how it would stop the half exactly?

Coolant is 3/4 full. Engine temp is normal, and the car has no other issues.

There is a ticking noise under the dash when the windscreen defog is selected, but it has done that since we have owned the car (5years) defog has always worked and still does (drivers side)

Anyone have any thoughts on what I could try next? I will take it to the mechanic if I have to, but trying to sort it myself first if I can. Save some coin.