Q&A

 Master

Your Automatic Climate Control is malfunctioning and needs to be scanned with a good MB capable scanner at a good MB independent shop. The Hot Air is usually a fail safe mode when the Auto Climate Control acts up. It is so people don't freeze in winter, but it is very uncomfortable in Summer.

I am having the same problem. Did you ever figure out what was causing the clicking noise. Mine still works great/blows cold just makes that noise if the switch is on high or in the blue/really cold a/c setting.

 Rookie

I am having the same problem in Chicago. The sound is un-nerving! Please let me in on the solution.

I had the same problem. The climate control switch had to be replaced and a few other things. It ran me around $1,700 for parts and labor at a local dealership, not what I intended to pay.

 Rookie

You have a faulty air blend door actuator. Google "detane" and "ML320" and you'll find a good video on how to replace it. It helps to have small hands to repair it this way. Otherwise you have to remove the entire dashboard.