My dad has a 2006 Cummins big horn. Whenever you turn on the fan switch all the way up to the highest setting it makes a sort of grunting noise. Still puts out air but not near what it used to. It really sucks when the windshield is frozen because there is barely any air coming out of the vents.

Any ideas???

 

Sounds like a problem I had a while back, and from what I found online it's a decently common problem with the Rams (I don't know at what point they fixed it).

There's a little flap, or door (under passenger side dash - behind glove box) that changes position when you choose fresh vs. recirculated air. The flap is supposed to be vertical (blocking off access to the interior of the truck) for fresh air, and horizontal (blocking the flow from outside) for recirculated air. There is a little motor that turns this door to each position, and the way it is attached to the door is the flaw. The motor turns a little rod that's about 3/4" long that is seated into a matching hole on the door. The other end of the door just rotates like a simple hinge. The problem is, the little "hole" that is on the door that accepts the rod from the motor is made from crap plastic. On mine, the plastic broke clean in half, so there is nothing holding the door in place. The door fell down, and was laying flat against the blower (at the bottom of the whole assembly blowing straight up) blocking most of the air flow.

I had the same problem, the air was the right temperature, and coming out of where it was supposed to, just not nearly as strong as it should have. I just pulled the door out (and the little piece of broken plastic that was lodged in the blower - how I was forced to solve the problem) and got full "blowing power" back. Sure, that's kind of a lame fix, because now I can't choose between fresh or recirculated air, BUT... I don't really ever care anyway.

You'll know this is the problem if, when you take the blower off from under the dash (simple, a few screws), there's a piece of plastic (mine was covered in foam) laying right there. Here's a pic of the door, broken piece and all.

Hope this helps.

 

My wife's minivan had that problem and it was the Heater blower resistor.

 

I just "fixed" this problem on my truck as well. It was making an aweful knocking noise when fan was on, for weeks. I was too busy to look at it. I was figuring the motor bearing was shot, pulled it apart and saw the little broken piece identical to the pic posted by Waterloo was in the squirrel cage rattling around. I just pulled the flapper out and threw the motor back in. Should be fine till warm weather hits then I can more comfortably glue the piece back on and slide the door back in.

 

Hey MoparGuy, good luck with trying to glue the piece back on. I couldn't find a glue (with what I had around the house) that would do it. It would just pop right back off.

 

Gorilla Glue makes a version of super glue. I used it to glue the motor casing back together of my miter saw thay fell off the saw horse and it has held up to the torque of the motor kicking on and off and also carrying the saw by its handle strains on where it was glued too...so I think this stuff should be able to do it...If not that I'll figure something else out.

 

I took the blower motor out, and that little piece is there So where do i find this flap that seperates fresh air from re-circulated? The noise is gone in the fan (cause i took the piece out), but there is still barely any air pressure coming out. Thanks everyone for your help!

 

Try these

http://www.turbodieselregister.com/f...-pictures.html

http://www.dieseltruckresource.com/d...d-t210483.html

 

Austin, once you've removed the blower motor the flap will be laying somewhere and oriented somehow in the cavity that is right above the blower, that is, where the blower is blowing. Mine happened to be laying flat blocking any flow from the blowing motor, hence the problem. There's a good chance yours is the same way. It may seem like it won't come out, but it's like a puzzle - flip it over every which way and it'll slide out vertically.