rear HVAC "clunk"
 

Turned on my rear AC the other day (like i always do) and there is a cyclical "clunk" or very heavy click that happens all the time when on in any position.

i'm guessing it is something in the blend door, because it happens in both the vent and floor positions, but is much quieter in the floor position. I tried changing the temperature from hot to cold and back but had no effect on the noise. wondering if the blend door motor is stuck "on' for some reason.

it's going into the shop wednesday, but i was kinda wondering if this is somewhat common, or if my lucky streak continues.

it has worked perfectly since i bought it, but apparently it didn't want to go to work at 4:30 that morning either ....

any ideas?

just found this:

might have to take some money away from my mechanic ... this actually looks like a very easy fix if i can get the part.

The blend door actuator for floor to ceiling takes about 5 minutes to replace. The part is $40-$45. Simple job.

it doesn't appear to be the floor-ceiling actuator. the noise changes when i switch from floor to ceiling, but it is still there, and i can hear the vents changing as well.

i'm going to poke around here tonight and see if i can locate what's making the noise, but i'm almost positive it is the heat/cold actuator that is giving me grief.

i ordered a new one through NAPA this morning for about $38. we'll see, i guess, if that's it or not.

It is quick to figure out which one it is - pull the change tray thing off the rear quarter trim and unplug the actuator on top which is the floor to ceiling. Noise stops, that's it. My guess is that is your issue since changing the selection does have an effect on the noise and the temperature knob doesn't. BTW - the actuators are different for each location - the axles are different. Some poeple have reported success getting to the temp one with the quarter trim still in place. If not you need to pull the hatch trim off first, then the quarter trim.

i pulled the connector to the directional door (top) and that stopped the clicking.

so i ordered the other one through NAPA shortly after confirming which one was broken.

i figured out the 7 step method of removing the control actuator.
1. remove coin tray and cup holder in passenger's side rear trim.
2. remove one bolt to the actuator
3. drop wrench beyond reach behind trim.
4. attempt to retrieve wrench and drop it all the way to the bottom of the trim panel
5. unload the rear of your truck and fold up the 3rd seat
6. pull trim back and retrieve wrench and socket separately in two steps.
7. remove the other two screws for the actuator.

i did take the actuator apart and saw the gears were stripped, so that's the problem.

have to break my mechanic's heart and tell him i don't need him for this one. Will have the part tomorrow, so i should be able to get it fixed for good tomorrow night if i get time to work on it.

on the plus side, i've got it directed to the roof vents and i can use the rear AC again, so my little man won't have to sweat it out in the back seat.

Just a heads up. I've found these units last 2-3 yrs. My first round of replacements were genuine Ford parts from the dealer. My second round were Dorman brand from the cheapest place I could find on the internet. My 3rd and "final" round is Dorman brand from my local Autozone with a lifetime warranty, at least now they'll be free to replace.

Without steps 3-6 it goes quickly and without much swearing.

Love the 7 step method, very funny!
My Ford dealer quoted $350 to replace the blend door; "oh, we have to take everything apart, it's all labor". Nuff said, the door was $35, took me 30 minutes.
2004 Expedition XLT 4x4...

good to note.

when i called my guy at NAPA he said he had two brands and asked which one i wanted, i said "i want the one with the better warranty"

brand "X" was a 3yr/36,000 mile warranty. the Dorman had a limited lifetime warranty and was only a dollar more.

as i told him, "that makes the warranty pretty cheap"

not sure if dorman is better or worse than the ford unit, but at least with a a decent warranty, you can take the chance for a part like this that isn't too hard to change out.

Big difference between blend door and blend door actuator, you are talking about a blend door actuator.

got it fixed here tonight.

for some reason the actuator for the directional door costs $10 more than the temperature blend door, even though they are exactly the same except for the shaft.

talk about getting the shaft ....

regardless, it is fixed and for about $50 and a few minutes worth of time. i'd call that success!

turns out that installation is exactly the same as removal, except that you can leave out steps #4-6.

Step #3 is still a critical step to the process. I wouldn't have done it otherwise.

just fixed mine last night in a 2005 Expy

the top "easy one" replacement part number is Dorman 604-213..got it at Oreillys for $52

came w/ lifetime warranty

works perfect

make sure when they look it up that the actuator is for the rear or auxillary and not the front....match the axles if any questions

don't depend on the employee...some don't have a clue

2 months later and the new one is stripped out as well.

something's got to be wrong somewhere.

i remember when i put the new on in that when changing to "vent" the motor has to push against the directional door VERY hard. i figured it was just for a tight seal, but the more i think about it ... it seems like something might be out of alignment and the motor is expecting the door to move farther than it actually does.

i'm going to order a new replacement motor (lifetime warranty), but i'm thinking i might take it apart and realign the gears so that the motor isnt pushing so hard against the damper door.

if that don't work i'm just going to put it in the vent position and disconnect the stupid motor.... i rarely want it on the floor anyway as all the heat just comes out of one spot, rather than across the whole rear of the vehicle.

will see ....

Where is it being bought from and who makes it?