I have a 95 S320 w/ 72K. I just turned on my heat for the first time this year, and I can't get any heat from the driver side vents. It only blows cold air from the driver vents. The passenger side vents work as normal and heats and cools as normal. Why can I only get heat from one side? Any suggestions? Thanks for your help and opinion in advance. Shayne

 

replace the duo valves.