2008 - Thumping noise coming from rear AC/Heat unit

[nathan faught]

I just got into my wife's 2008 tonight and when I cranked it up and turned the radio down I could hear a small thump coming from the AC/Heat unit in the back on the passenger side.

I took the tap tray piece off and the cup holder out but still cant pinpoint where it's coming from.

What could be causing this. The AC and heat still seem to work as expected so is this anything hurt by this thump/click and how difficult is this to fix?

Thanks!

 

[Bedrck47]

Sounds like you have a bad Temperature Blend or Mode Door Actuator. Easy to replace. Look on youtube for videos on how to replace it.

 

[nathan faught]

Sounds like you have a bad Temperature Blend or Mode Door Actuator. Easy to replace. Look on youtube for videos on how to replace it.

If I don't change the immediately what is the harm?

 

[Bedrck47]

Only harm is listening to the thumping But you can check it and find out which actuator is at fault and disconnect the connector

 

[Denethor]

Or you can slightly adjust the temp to that zone, so it stops trying to move the blend door to the bad spot on the gear (it can't anyway). Like on mine, just not cranking it all the way to cold (I just go to full cold, then back off one click of the dial it stops the thumping). The only 'harm' is the door can't move past the broken tooth on the gear (the thumping you hear is one plastic gear tooth slipping past another) and the temperature coming out of the rear will not be as hot or as cold as it could be.

 

[nathan faught]

you guys are great. thanks for the advice.

 

[Bedrck47]

Or you can slightly adjust the temp to that zone, so it stops trying to move the blend door to the bad spot on the gear (it can't anyway). Like on mine, just not cranking it all the way to cold (I just go to full cold, then back off one click of the dial it stops the thumping). The only 'harm' is the door can't move past the broken tooth on the gear (the thumping you hear is one plastic gear tooth slipping past another) and the temperature coming out of the rear will not be as hot or as cold as it could be.

That would work for the temperature blend door but not for the mode door And the OP never stated which door was doing the thumping.

 

[nathan faught]

I'm not quite sure which is thumping. But if the fix is only $100 or so, I might as well do it just to have it working properly.

My wife would never even notice things weren't working most likely...

 

[Bedrck47]

There are two actuators the one towards the frond is the mode door it directs air to the floor or to the roof vents The one towards the rear is the temp blend door Check on rock auto for the parts But they may be different due to the wheelbase of the model you have. May be best to just pull the bad part and get the part number off of it and that way you will get to correct actuator.

Check the video on youtube and having the wrench that the Ford tech uses is very helpful

On my 04 both actuators are bad I currently have them removes and wired the doors to the position I need them to be in.
When I get the new parts I will install them Most likely when the weather get better In the meantime I now have plenty of heat in the rear of the expy and no thumping noise

 

[Y2KFirehawk]

Was searching for something else, but figured to share the aforementioned video here

2003-2006 Ford Expedition: Rear HVAC Temperature Blend Actuator Clicking Repair

This is the actuator needed for the repair-2003-2004-http://www.amazon.com/gp/product/B004A2D4WA/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=...

www.youtube.com