I have an 03 FX4 Expedition. When the key is on, engine running or not, there is a thumping noise behind the lower right rear interior panel. With closer inspection there is a motor running and the "thumping" noise sounds almost like a wiper motor with something stuck. I have a suspicion that it might have something to do with a fresh air door on the rear AC unit not closing or opening properly. I cant even figure out how to get this panel off. It covers a pretty large area. Any suggestions or feedback?

Thanks

 

The whole right rear panel has to come off. Seatbelts off, all plastic panels off, its a biatch to do. Ihad them do it to my 98 to replace the sub that was blown.

 

Same thing just started with my 04' expy. did you have this same thumping noise 98 Navi or where you working on your speakers.

I wonder what is causing the thumping noise. Of course I'm out of warranty by 2000 miles when this starts! Hopefully we get some feedback on this.

 

Is your rear AC unit ON or OFF or both when you hear the noise?

 

There is alot of information about this on another ford discusion site. The problem seems to be a blend door motor on the rear AC unit. There is two of these motors located in the right rear of the Expy.

I was able to pop out the cup holder and see the motor that is thumping on mine. I got lucky because the other motor that is prone to the same problem is not as easy to reach as the one directly under the cup holder. You can also pop out the tray that is back there, just do it slowly, it's plastic you know. Actually I popped out the rear tray first and then was able to get a hand under the cup holder and push it out. Both of the plastic pieces are tight but should pop out with a little force.

It's a white motor that has been redesigned supposedly, so if you replace it with a new one from ford it should hold up better. I have not actually replaced the motor yet, but it looks relatively easy. I will post more when I replace it.

 

Any new info on this subject? My 03 just started doing this.

Thanks.

 

My 03 expy did this last year. I pulled up the cupholder or tray on the right rear and found the little white motor clicking. Mine only did it when the rear air was on. Luckily this happened just before the warranty ran out, so Ford replaced it for free. It only took about 10 minutes to replace. I don't remember what the invoice said the price was, but I think it was fairly cheap if you're out of warranty. No problems since.

 

Mine was out of warranty so I had to do it myself. The motor cost $68.00.
You can reach both motors if you pull out the cup holder and tray, they both just pop out. The motor that was not working on mine was the one on the side, not the motor under the cupholder. It's not as easy to reach, but you can get to it if you work some of the plastic moldings lose. This is the part that I wasn't sure of. I was worried I would break em. Get with someone who does some work on sterios or aftermaket interior gadets, they are used to pulling these moldings off and understand the basis of how they are attached to the vehicle. But basically they pop off, thats how they are installed initially.
Anyway once you get the side molding pulled back far enough to reach the side mounted motor it's as simple as unscrewing it from the base, pulling it out, unpluging the wiring, and repeat in reverse to install the new motor. It's helpful to have someone help hold the plastic side molding back as you unscrew the motor housing from the base it's attached to. Unless you happen to have small hands and arms.

Now as to why it wasn't working in the first place. After I installed the new motor I took the old motor apart to see why it wasn't working properly. It turned out to be a plastic gear inside the motor that the teeth had broken off of. So with my vehicle I had the thumping noise and couldn't get warm air to blow in the rear of the vehicle, that was because the gears were stripped inside the motor housing that controlled the blend door position. The motor itself worked fine, but it couldn't open or close the blend door because the plastic gears were stripped off. The blend door thumped because of the the vacuum pressure on it. So I spent $68 to replace the 25cent plastic gears that stripped off.

Works great now!

 

Okay thanks guys for the info. I think mine is the one directly under the cup holder.

 

Hi there,

Do you happen to have the part number...My wife's 2003 Expo has the same problem...thanks