Hey fellas,

So i have an issue with the heating system in my 2013 S6. it started this winter i turned on the heater when i started the car in the morning and no heat. i got in the car and started driving and all the sudden it started blowing heat but only out of the driver side. As soon as i stopped at a traffic light it started blowing cold air. The driver side is the only side that will blow warm when driving, passenger side only blows cold air. Any insite would help or where to start looking.

thanks folks.