The fan on my truck hasn't worked so well recently. In fact, it's been somewhat intermittent. Today I finally tore into it to figure out what's up. I'll save the long, drawn-out story, but there's a flap of some sort that lives above the blower motor that has broken. It was moving about freely. you could stick your fingers into the intake hole and feel it, slide it around, lift it up, etc.

We removed the blower motor and a friend was able to reach up in there and remove the flap, as well as a broken piece of plastic that appears to be part of a hinge on the flap.

I used to have a PDF service manual, but I can't find it anymore. Anybody know what this flap is and does? If the part is available cheaply, I'll order a new one. Otherwise I think I can JB Weld the thing back together and reuse it.

Rob

 

The flap directly above the blower motor is the recirculation door.

If you remove the glove box, you will see the intake grille for recirculation mode. Looking up through the motor hole, you will see the fresh air intake. That door just blocks one and opens the other, depending on mode selection.

There are electric motors that drive couplers that drive the various hvac doors. A tab moulded into the case is supposed to stop the coupler from over traveling and breaking the doors.

Blend doors are also a known failure point, a pair of doors that direct air through or around the heater core in response to heat setting.

I think there was an updated part for the upper and lower hvac case. A company called heater treater also makes replacement doors out of metal.

Normal repair would require draining coolant, evacuating AC, and removing dash. That might not be required for just the recirc door. Heater treater I think has a scheme for cutting into the hvac case to replace doors without taking the case out.

 

Thanks!!!! That's a huge help.

I have the broken door drying right now (JB Weld) but it sounds like this isn't going to work anyway. But the four-door replacement route is $254. Ouch (or $119 for the current one). Think I'll be going w/o Recirc for another month or so til I can afford to get all four.

Rob

 

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

Above is a nice write up about the hvac system that might be helpful.

A person could probably just masking tape off the recirc intake for now.

Taking the dash out isn't overly difficult, but takes 4-5 hours.

 

Thanks! Good info.

Well I JB Welded the door and it seems to be a good fix, but I can't get it back in place. I removed the servo motor so I could remove that white piece (as shown in the writeup in the link posted in #4), but that white piece isn't coming out, at least not without either removing the entire HVAC housing or breaking the thing in the process. Disgusted, I just reassembled everything without the door and the blower works just fine. Sure I don't have recirc, but at this point, I don't care. It'll last until I can afford the Heater Treater stuff.

Rob

 

Yeah, if you are going to have a door break, that's the one you can get by without.