I'm looking to buy a truck and i found one i like. its a 06 3500 slt mega cab single rear wheel 101k miles. the only problem is when i took it for a test drive and turned the air on the vents it blew harder on the driver side than the passenger side. it also took a little longer for it to turn from the floor vents or face to the defrost. anyone know what it would be or how much it could cost to fix.

 

Blend doors. Pretty common issue. They make steel replacement doors or you can mod it yourself. Do a search on here. All sorts of posts.

 

Really not a big deal if you like the truck, I love my 06.

 

The mode door controls where the air comes out. The blend door controls the air temperature. The recirc door either lets in outside air or uses the cab air. All have been known to break. So far on my 06, I've only had the recirc door replaced.

As said, if the truck is sound otherwise, I'd not let this issue stop the purchase. Good luck!

 

Knock on wood, my 07 seems to be working fine. AC, blend door, mode door, etc.
One thing that I found to help the doors switch positions is to leave the fan on low or off when changing modes. Less air flow seems to help the doors move better/quicker.