Burning rubber smell on the drivers side of my 2003 kia serento what is it?

SOURCE: 2004 chevy subarban blows cold air on one side hot air on other side

i was a GM mechanic for many years, the problem you are having is one of your mode door actuators has gone bad, most of the time it is the actuator on the drivers side that causes the problems, i have seen this many times, sometimes you can take it to the dealer and they can hook the computer up to it and recalibrate it but most times it has to be replaced , it is located under the dash in the area above your gas pedal.

SOURCE: A smell of burning rubber

A common cause of a smell like that is a coolant leak.Take a close look around the hoses,clamps, frost plugs and the water pump as it has a weep hole that will leek coolant if the seal is breached. Sometimes all you will see is a stain, but no coolant as small leeks boil away with the engines heat.
If a belt was burning it would be very noisy. The timing belt is cogged so slippage is unlikely. It is possible that a foreign object has gotten on the exhaust manifold like a plastic bag. One last thing I can think of is a wire or something touching a hot surface and melting. Good luck.

SOURCE: Bad smell coming from heater/ smoke coming out vents

I had the same problem in my 98 Dodge Dakota! Replaced the heater core, problem solved. No more funky coolant smell and erie fog coming through my vents. I bought the heater core at rockauto.com online. Have purchased many items now from them. All factory parts so far at half the price of even AutoZone, even with the shipping. Also, you usually have to wait only a couple of days depending on the part and they have EVERYTHING.

SOURCE: Burning rubber smell inside car-2003 CTS Cadillac

Diagnosing this will be subject to a process of elimination. It could be the radio, blower motor or any other accessory particularly ones with moving parts; Try switching those off and try to note when this problem occurs and what is on/whatyou are doing. Something is getting hot causing the smell so it will be a situation where the accessory will have to run a while before doing it. It is a possibility that there is an electical curcuit overheating, but less likely. Lets rule out accessories first and give us an update. GL

SOURCE: 2003 accord air conditioner

I ad this problem fixed and it cost $35. Apparently, this happens when the Freon level is low for some reason. They refilled the Freon and now I have AC on both sides. Don't forget to replace the internal filter in the glove box.