HVAC removed and understood!
07-08-2008, 01:35 PM
#1
HVAC removed and understood!
I have an '03 gas 2500 extended cab that quit blowing heat on my feet last winter. I finally decided to take it apart and find out what's wrong. I followed the instructions I found on the turbodieselregister.com site. (http://www.turbodieselregister.com/f...d.php?t=166129) I also found this article as a pdf someplace and saved it to my hard drive. I would reattach it here if I knew how. I'll attach some pics of my own and show you what I found on MY system.
Here's the unit on the bench as would be seen from inside the vehicle.
Moving from the left, there are four actuators.
The fartherst left unit operates a flapper that switches between air blowing on the floor or out the top end of the HVAC unit to what I believe is the defrost vents. This door cannot be seen with the HVAC unit in the truck even with the dash pulled back. This door is known to have issues and I suspected mine did too.
The next actuator from the end operates a door that opens or closes the panel vents. This door can be seen from the top when the HVAC unit is in the vehicle and the dash is pulled back. Mine appeared to operate just fine.
The next actuator from the left operates TWO doors that either send air through the heater core OR bypass that air around the heater core. The core is sandwiched in the middle and there is a door on either side.
The fourth actualtor operated a door that either recirculates the blowing air from the cab or allows outside air to be pulled into the cab. It is on a removeable housing on the far right end of the HVAC unit. This door is known to break and fall out of position. It can be seen from the top when the HVAC unit is in the truck and the dash pulled back. It can also be felt/seen from below if the fan is removed. Mine appeared to be operating just fine.
I pulled all actuators noticing that they all only had two of three screws installed! Is this normal? I pulled the air deflector off the bottom of the housing that routes air to the left and right portions of the floor. Once this is off, one can see the floor/defrost door. Mine looked ok.
I examined the coupler (white piece that connects the actuator to the door through the housing) and the housing around the actuator. I found the housing had the full stops as shown on the Turbodiesel registry pdf, but the coupler had a stop tang broken off!
Jeff
Here's the unit on the bench as would be seen from inside the vehicle.
Moving from the left, there are four actuators.
The fartherst left unit operates a flapper that switches between air blowing on the floor or out the top end of the HVAC unit to what I believe is the defrost vents. This door cannot be seen with the HVAC unit in the truck even with the dash pulled back. This door is known to have issues and I suspected mine did too.
The next actuator from the end operates a door that opens or closes the panel vents. This door can be seen from the top when the HVAC unit is in the vehicle and the dash is pulled back. Mine appeared to operate just fine.
The next actuator from the left operates TWO doors that either send air through the heater core OR bypass that air around the heater core. The core is sandwiched in the middle and there is a door on either side.
The fourth actualtor operated a door that either recirculates the blowing air from the cab or allows outside air to be pulled into the cab. It is on a removeable housing on the far right end of the HVAC unit. This door is known to break and fall out of position. It can be seen from the top when the HVAC unit is in the truck and the dash pulled back. It can also be felt/seen from below if the fan is removed. Mine appeared to be operating just fine.
I pulled all actuators noticing that they all only had two of three screws installed! Is this normal? I pulled the air deflector off the bottom of the housing that routes air to the left and right portions of the floor. Once this is off, one can see the floor/defrost door. Mine looked ok.
I examined the coupler (white piece that connects the actuator to the door through the housing) and the housing around the actuator. I found the housing had the full stops as shown on the Turbodiesel registry pdf, but the coupler had a stop tang broken off!
Jeff
07-08-2008, 01:43 PM
#2
I also tried rotating the coupler by hand and noticed that it would spin inside the door. Apparently the door or coupler was stripped. I then removed all the screws between the top and bottom portions of the HVAC housing. and carefully separated them.
One end:
Other end:
I had to carefully depress three or four tabs and push the coupler out of the HVAC housing and out from the floor/defrost door. The door then pulled free of the housing. The coupler looked OK where it slid into the door, but the door mating area was stripped.
So, I decided my lower HVAC housing was ok since it had the full stops molded in. I need to order a coupler and door though. I then examined the trouble prone recirculate housing and noted that it did NOT have the molded in door stops of the newer housing as shown in the pdf I was following.
The bottom part of the housing did look like the newer housing shown in the pdf though.
Since the housing with door was only 17.06 through moparpartsamerica.com I decided to go ahead and get that too even though mine was still ok.
So, I ordered three parts:
5073964AA Defrost door $21.56
5019632AA Coupling $5.25
68004226AB Recirculation housing w/door and actuator $17.06
Total $43.87
Shipping $8.95
Total $52.82
Jeff
One end:
Other end:
I had to carefully depress three or four tabs and push the coupler out of the HVAC housing and out from the floor/defrost door. The door then pulled free of the housing. The coupler looked OK where it slid into the door, but the door mating area was stripped.
So, I decided my lower HVAC housing was ok since it had the full stops molded in. I need to order a coupler and door though. I then examined the trouble prone recirculate housing and noted that it did NOT have the molded in door stops of the newer housing as shown in the pdf I was following.
The bottom part of the housing did look like the newer housing shown in the pdf though.
Since the housing with door was only 17.06 through moparpartsamerica.com I decided to go ahead and get that too even though mine was still ok.
So, I ordered three parts:
5073964AA Defrost door $21.56
5019632AA Coupling $5.25
68004226AB Recirculation housing w/door and actuator $17.06
Total $43.87
Shipping $8.95
Total $52.82
Jeff
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SmokemS (06-20-2022)
07-08-2008, 02:16 PM
#5
The pdf I referred to can be found in post 11 of this thread:
https://www.dieseltruckresource.com/...ht=temp+sensor
Jeff
https://www.dieseltruckresource.com/...ht=temp+sensor
Jeff
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07-13-2008, 12:14 AM
#13
Registered User
I think love you!! I've been on this puter all day looking for pictures like these. I wish I knew how to troubleshoot all the electrical controls before tearing the dash and hvac box out just in case my problems aren't all mechanical - broken stops, couplers and doors but I haven't read about ANY electrical problems except maybe for pulling the IOD fuse to zero and span the actuators. I can't find an IOD fuse in my 03, anyway! Doesn't mean it isn't there, tho. I think I read in one post that there's a complete box with new actuators, doors and everything in it except the coil and core. Anyone know about that? Craig
07-14-2008, 10:53 PM
#14
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As I posted on the other thread, thanks for the work on your excellent write up.
07-17-2008, 10:39 AM
#15
Just as a folowup, I got my parts and installed them last night.
Here's a couple pics of the new door and coupler:
I guess I didn't take a pic of the new recirculate housing, but it looks just like the old one plus a stop for the coupler. One interesting thing is that it also came with only two screws holding the actuator on. I guess that's just they way they are.
When reinstalling all the actuators I had removed, they didn't seem to want to fit with their corresponding flappers fully closed or open, so I ended up setting the HVAC housing on the truck seat with the actuators plugged in, but not screwed in place and the HVAC wiring harness plugged into the truck. Doing this I was able to move the controls around and watch the actuators to see what happens. I found out through trial and error that once screwed on, they seem to find their limits through cycling through the modes a couple times. Eventually I had all the actuators installed and when I walked through the modes, they would all move to their fully on or off positions. I then reinstalled the housing in the truck, buttoned up the dash and tried things out. All positions work great!!!!!!!!!! Lets hope it stays this way for the duration!!!!!!!!!!! I've got to get the A/C system recharged now. Oh, two slight clarifications I would like to make on this procedure are:
On my gas truck I had to pull a computer from the under dash area to get at the second mounting stud for the HVAC unit. I pulled the air intake box to make things much easier to get at.
When putting the dash back in for the final time, make sure the ebrake release rod is sticking through the hole aiming at the handle before installing the screws/bolts.
Jeff
Here's a couple pics of the new door and coupler:
I guess I didn't take a pic of the new recirculate housing, but it looks just like the old one plus a stop for the coupler. One interesting thing is that it also came with only two screws holding the actuator on. I guess that's just they way they are.
When reinstalling all the actuators I had removed, they didn't seem to want to fit with their corresponding flappers fully closed or open, so I ended up setting the HVAC housing on the truck seat with the actuators plugged in, but not screwed in place and the HVAC wiring harness plugged into the truck. Doing this I was able to move the controls around and watch the actuators to see what happens. I found out through trial and error that once screwed on, they seem to find their limits through cycling through the modes a couple times. Eventually I had all the actuators installed and when I walked through the modes, they would all move to their fully on or off positions. I then reinstalled the housing in the truck, buttoned up the dash and tried things out. All positions work great!!!!!!!!!! Lets hope it stays this way for the duration!!!!!!!!!!! I've got to get the A/C system recharged now. Oh, two slight clarifications I would like to make on this procedure are:
On my gas truck I had to pull a computer from the under dash area to get at the second mounting stud for the HVAC unit. I pulled the air intake box to make things much easier to get at.
When putting the dash back in for the final time, make sure the ebrake release rod is sticking through the hole aiming at the handle before installing the screws/bolts.
Jeff