Forgive me if this question has been posted before, but I'm new to this forum.

I have a 2001 Dodge Ram 5.9L 4x4 and my vents are stuck on defrost. The controls work to turn it on/off, temp adjust and blower speed, but the vents won't shift over to floor, bi-level, or face level.

I took the control assembly out and put a test light on it, and only a few circuits lit up, but I was told the vents shift over under vacuum pressure?

Is this vacuum leak problem, or should I replace my control assembly? I'm not sure how to proceed.

If anyone has a solution please let me know. I'm new to working on my truck so please be specific.

Thanks so much in advance!

 

pop your hood.....look for a vacuum leak or broken vacuum line on your pass side. there is a line that comes off the intake and t's into the firewall, they are your vacuum lines that control your changing of the vents. inspect them and see where you stand.

 

pop your hood, now go to your pass side, you will see vacuum lines that come off your intake that run towards the firewall, check those for and leaks or breaks as they are your vacuum controls for your heater box

 

Use the search button and search for "Wild Vents" there is a 15+ page thread around there detailing the problem very well. You probably have a bad check valve on the passenger side of the intake. Get one from the dealer as the parts store ones are garbage.

 

the same thing happened to mine. Pass side bout 6 inch plastic vaccum line easy fix.