Can someone explain to me exactly how the recirculate works? I am having a major dust issue when travelling gravel roads in my 2015 ram and i'm at a loss. I do have a cabin filter installed and that doesn't help. I believe it's coming from the back but not 100% sure. This being summer time, i keep it on max a/c and recirculate. Doesn't that close vents from the outside? I'm just trying to understand the system itself and eliminate things as i go. The thing i have done last summer was the pull the back seat out and put a filter cloth on the vents in the back of the cab...might of helped but did not stop the problem completely. I do not want to block all the cab vents but would like to reduce this issue. The other question i have is in regards to the small looking vents on the "body" when you open the back doors at the bottom. What are those for? I popped both of them out and it's completely loaded with dust making me think that might be the culprit but not sure if i can block them or not.

Thanks in advance.

 

Fantastic question. I've noticed a lot of dust and pollen buildup in my 2017 Crew as well with the A/C running in the recirculate. New cabin filter installed. I am not privy to those vents you are referring to though...