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Another AC flipper door dead!!!
- Thread starter DDT
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heatertreater.net
Go to this web-site and buy their parts... they have a VERY comprehensive diagnostic/troubleshooting section to determine exactly which door is broken...
I bought all the doors for my truck. Replaced the one that had failed and have the other two already on-hand for when the factory junk fails.
Go to this web-site and buy their parts... they have a VERY comprehensive diagnostic/troubleshooting section to determine exactly which door is broken...
I bought all the doors for my truck. Replaced the one that had failed and have the other two already on-hand for when the factory junk fails.
Not too sure the exact problem you're refering to, and the below link isn't the TDR mag, but it may be of some use as I replaced all my HVAC doors with Heater Treater. Hope it helps.
https://www.turbodieselregister.com...93-hvac-heater-treater-doors-replacement.html
https://www.turbodieselregister.com...93-hvac-heater-treater-doors-replacement.html
There is only one motor just above passenger feet. Double check your recirc door. When mine broke it dropped over the inlet to the blower motor and I wasn't getting much air to anywhere. When you remove the blower motor, (three screws and disconnect two electricals) you can reach up into the inlet and feel the door to check if it is in place.
put the fan on high with the mode in "fresh air" in other words, NOT recirculate..... blowing out of dash vents... (not floor and not defrost) listen to the sound the fan is making... . see if it sounds normal. Then switch to recirculate, the fan pitch should change... . all the while, there should be large volumes of cold air blowing out of the dash vents. . both times my recirc door failed, the fan noise was significantly different. . I guess due to the door laying down inside the box . . at high speeds it would actually whistle...
It seems that the recirc door is the most common to fail, (mine failed twice before I bought the HT stuff) and its the easiest to fix.
You can pull the glovebox out and look directly into the top of the air box and verify that... .
1) the door is still attached at both ends
2) that when you call for fresh air vs. recirculate that the stepper motor actually moves the door from fully open to fully closed.
The door could be still attached but not making the transition from one mode to another... .
I think the blend door is immediately below that, but not 100% positive...
I have most the dash out of the way, I can see the recirculate door ( passenger side at the top). This door is soild when trurning axle of door both ways,There is stops both directions. motor works on 9 volt battery, installed the motor and pulged in the controls, theis door works each way... . So whats next????
Here's the Heater Treater link that will help you diagnose the problem. There are four doors, each has different symptoms:
Dodge Ram 2002, 2003, 2004, 2005, 2006, 2007, 2008, blend door auto AC heat replacement part
Dodge Ram 2002, 2003, 2004, 2005, 2006, 2007, 2008, blend door auto AC heat replacement part
1. Re-circ door.
a. This door regulates between external air and internal air being pulled into the system. It works by blocking the external intake vent, forcing air to be pulled from the internal intake vent, OR blocking the internal intake vent, forcing air to be pulled from the outside. There is no in between. You can easily check the function by turning the fan on full blast and checking the air flow into the external vent between the hood and windshield. With re-circ off, you should feel a strong air flow into the vent and it should stop when re-circ is on. When the door fails, it hangs in the center and both the external vent and internal vents are open and air will flow into the external vent and out of the internal vent…like having a window rolled down all the time. If you feel air coming in under the passenger side dash, this is most likely the problem.
b. The photo shows the location of the re-circ door behind the glove box opening. The door is covered by a grate and is in the upper right hand corner. You can easily see/feel the door move when you have the system on and switch re-circ on and off. If the door doesn't move or is missing, add this one to the list.
2. Blend door.
a. The blend door's function is to divert some, or all, of the air flow through the heater core. The RAM uses an odd, complex method with two blend doors. The heater core is on a horizontal plane and two doors are sandwiched on the top and bottom of the core. In full AC, both doors close against the core(top down, bottom up) and block any air flowing through the core. In full heat, air is diverted through the core with the top door and the bottom door away from the core. This blocks normal air flow in the bottom of the box, forcing more air through the top and down through the heater core. The doors blend the air by partially opening and forcing some air through the core with some bypassing the core through the bottom door. The two doors are linked together and operate in unison to control temperature.
b. The symptoms of blend door failure are an inability to control the temperature of the air flowing through the system. A broken door will generally fall into the down position, blocking the core and having no heat in the system. The box is designed for either single or dual control of temperature on the passenger and driver's sides. If there is a difference between passenger and driver's side temperatures, the problem is with the blend door on either a single or dual control system. Of course this test assumes that the heater core is hot. You want to make sure that the radiator is full(radiator, not overflow tank) which you can check by opening the radiator cap on a cold engine. The radiator should be full, air in the system will greatly diminish heater operation and engine cooling. You can also check the heater hoses from a cold startup. The two hoses going into the firewall should warm up at about the same rate and get uncomfortably hot. This is a good indication that coolant is flowing through the heater core.
c. The RAM plenum box is built with dual air flow chambers so that the system can be configured for either single or dual control. On the single control, the blend doors are just connected together and operate as a single unit, but there are still two separate air flow chambers. The single control has a single actuator motor to control both sides of the HVAC system while the dual control has separate motors for either side. Air flows through the AC evaporator core before getting to the dual chambers and if there is a temperature differential across the core, it can show up as a difference in temperature on the two sides. Most auto makers constructed the core with refrigerant flowing from top to bottom on dual systems. With this setup both sides would be the same and a lack of efficiency in the core would be equally spread across both sides. Chrysler moves the refrigerant from right to left, so if there is a temperature gradient across the core, the passenger side is at the back of the core and will see less efficient AC. Charging the system may solve the problem and at least it should be checked. If the charge is too high or too low, it can cause a gradient across the core and it will show symptoms of warmer air on the passenger side. This is a design flaw in the system and there is little margin for less than perfect operation of the AC compressor system. You may have to “tune” the refrigerant charge, monitoring temperature on both sides, to get it perfect. If the refrigerant charge is OK, the next suspect is the blend doors. Dodge has a strange clam shell door arrangement for the doors in the RAM. There are two doors, an upper and lower that move in unison and cover the top and bottom of the heater core which is on a horizontal plane. On a single control system there are four different flaps(two sides/two sets of doors) that have to operate correctly. The plastic components are susceptible to breakage and it is an expensive repair to remove and repair the plenum box when this inevitably happens. The back door can break off exposing the top or bottom of the heater core to the air flow. The system will still operate, but the added radiant heat from the core can significantly affect passenger side cooling. The only way to really diagnose this problem is to cut into the box and observe the operation of the doors. Once you have the box open, you can also check the temperature of both sides of the AC evaporator core to make sure that it is cooling both sides efficiently. It takes a little work to get to the doors and check the operation, but once you understand the root cause of the problem, it can be restored to fully efficient operation.
3. Mode Door 1.
a. This door regulates air flow to either the dash vents or defrost/floor. If you have air flowing only through the vents with no defrost or floor, this door is failing. From our experience, this door is usually the first domino to fail. Not sure why, just is.
4. Mode Door 2.
a. When mode door 1 is set to divert air away from the vents and into the second stage of the system, door #2 chooses whether air goes to the defrost vents to the windshield or out through the floor vents in the passenger and driver's side footwells. Failure is indicated by an inability to choose between defrost and floor.
b. This door turns out to be the most difficult to replace. In order to replace the door, the dash panel has to be removed. It's still better than the dealer fix because you don't have to evacuate the AC system, drain the radiator, and remove the plenum box. But it is more work than the other fixes. When this door breaks, it falls in the down position, blocking the floor vents and diverting all air through the defrost vents. From a safety standpoint, this is good since you'd most likely rather have a clear windshield than warm feet. We suspect that a large percentage of customers will just leave this door unrepaired. You will have heat through the dash vents and to the windshield, just nothing to the floor. It's inconvenient, but you'll have to make the determination if warm feet are worth the extra work to fix the door. An extra pair of socks is easier.
a. This door regulates between external air and internal air being pulled into the system. It works by blocking the external intake vent, forcing air to be pulled from the internal intake vent, OR blocking the internal intake vent, forcing air to be pulled from the outside. There is no in between. You can easily check the function by turning the fan on full blast and checking the air flow into the external vent between the hood and windshield. With re-circ off, you should feel a strong air flow into the vent and it should stop when re-circ is on. When the door fails, it hangs in the center and both the external vent and internal vents are open and air will flow into the external vent and out of the internal vent…like having a window rolled down all the time. If you feel air coming in under the passenger side dash, this is most likely the problem.
b. The photo shows the location of the re-circ door behind the glove box opening. The door is covered by a grate and is in the upper right hand corner. You can easily see/feel the door move when you have the system on and switch re-circ on and off. If the door doesn't move or is missing, add this one to the list.
2. Blend door.
a. The blend door's function is to divert some, or all, of the air flow through the heater core. The RAM uses an odd, complex method with two blend doors. The heater core is on a horizontal plane and two doors are sandwiched on the top and bottom of the core. In full AC, both doors close against the core(top down, bottom up) and block any air flowing through the core. In full heat, air is diverted through the core with the top door and the bottom door away from the core. This blocks normal air flow in the bottom of the box, forcing more air through the top and down through the heater core. The doors blend the air by partially opening and forcing some air through the core with some bypassing the core through the bottom door. The two doors are linked together and operate in unison to control temperature.
b. The symptoms of blend door failure are an inability to control the temperature of the air flowing through the system. A broken door will generally fall into the down position, blocking the core and having no heat in the system. The box is designed for either single or dual control of temperature on the passenger and driver's sides. If there is a difference between passenger and driver's side temperatures, the problem is with the blend door on either a single or dual control system. Of course this test assumes that the heater core is hot. You want to make sure that the radiator is full(radiator, not overflow tank) which you can check by opening the radiator cap on a cold engine. The radiator should be full, air in the system will greatly diminish heater operation and engine cooling. You can also check the heater hoses from a cold startup. The two hoses going into the firewall should warm up at about the same rate and get uncomfortably hot. This is a good indication that coolant is flowing through the heater core.
c. The RAM plenum box is built with dual air flow chambers so that the system can be configured for either single or dual control. On the single control, the blend doors are just connected together and operate as a single unit, but there are still two separate air flow chambers. The single control has a single actuator motor to control both sides of the HVAC system while the dual control has separate motors for either side. Air flows through the AC evaporator core before getting to the dual chambers and if there is a temperature differential across the core, it can show up as a difference in temperature on the two sides. Most auto makers constructed the core with refrigerant flowing from top to bottom on dual systems. With this setup both sides would be the same and a lack of efficiency in the core would be equally spread across both sides. Chrysler moves the refrigerant from right to left, so if there is a temperature gradient across the core, the passenger side is at the back of the core and will see less efficient AC. Charging the system may solve the problem and at least it should be checked. If the charge is too high or too low, it can cause a gradient across the core and it will show symptoms of warmer air on the passenger side. This is a design flaw in the system and there is little margin for less than perfect operation of the AC compressor system. You may have to “tune” the refrigerant charge, monitoring temperature on both sides, to get it perfect. If the refrigerant charge is OK, the next suspect is the blend doors. Dodge has a strange clam shell door arrangement for the doors in the RAM. There are two doors, an upper and lower that move in unison and cover the top and bottom of the heater core which is on a horizontal plane. On a single control system there are four different flaps(two sides/two sets of doors) that have to operate correctly. The plastic components are susceptible to breakage and it is an expensive repair to remove and repair the plenum box when this inevitably happens. The back door can break off exposing the top or bottom of the heater core to the air flow. The system will still operate, but the added radiant heat from the core can significantly affect passenger side cooling. The only way to really diagnose this problem is to cut into the box and observe the operation of the doors. Once you have the box open, you can also check the temperature of both sides of the AC evaporator core to make sure that it is cooling both sides efficiently. It takes a little work to get to the doors and check the operation, but once you understand the root cause of the problem, it can be restored to fully efficient operation.
3. Mode Door 1.
a. This door regulates air flow to either the dash vents or defrost/floor. If you have air flowing only through the vents with no defrost or floor, this door is failing. From our experience, this door is usually the first domino to fail. Not sure why, just is.
4. Mode Door 2.
a. When mode door 1 is set to divert air away from the vents and into the second stage of the system, door #2 chooses whether air goes to the defrost vents to the windshield or out through the floor vents in the passenger and driver's side footwells. Failure is indicated by an inability to choose between defrost and floor.
b. This door turns out to be the most difficult to replace. In order to replace the door, the dash panel has to be removed. It's still better than the dealer fix because you don't have to evacuate the AC system, drain the radiator, and remove the plenum box. But it is more work than the other fixes. When this door breaks, it falls in the down position, blocking the floor vents and diverting all air through the defrost vents. From a safety standpoint, this is good since you'd most likely rather have a clear windshield than warm feet. We suspect that a large percentage of customers will just leave this door unrepaired. You will have heat through the dash vents and to the windshield, just nothing to the floor. It's inconvenient, but you'll have to make the determination if warm feet are worth the extra work to fix the door. An extra pair of socks is easier.
Frequently if the drivers side is cold but the passenger side isn't you are a bit low on refrigerant. If you go to Walmart you can buy a device that will tell you the pressure and let you charge it by screwing a can of R-134a onto it. Last year it ran about $17 for the dispenser (don't buy the kit that has the R-134a in it because it has a leak sealer). I forget who makes it, but it has a hose that runs to what looks like the trigger mechanism on a bottle of spray window cleaner, and has a gauge on top of the trigger mechanism. You attach it to the low side connection (passenger side, just below the windshield) with the AC on recirc, max fan after it has been running for 5-10 minutes. If the pressure is low you disconnect it, thread a can of refrigerant on to the dispenser and reconnect it. Then, while you are rotating the can upside down and back again you squeeze the trigger. Every few seconds release the trigger and check the pressure. Don't over fill it or your compressor will work too hard.
I use ( this time of year) the dash vents only a/c is on to. This works fine until 30 minites or so the air stops blowing from the vents, the air is dircted to the passenger side floor with no air from the defrost vents. I turned controlknob the defrost and no air goes to the windsheild, turn the control knob different locations and there is no difference in air flow.
Today I checked the Re-cir door, motor works both ways with 9 volt battery test, the door moves from open to closed using the axle to turn it, no slippage there. the gear mesh on the motor and the axle look unharmed. I even removed heater motor to get room for my hand to the door, seamed soild.
I reinstalled this motor and pulged in control panel, this door worked like it is suppose to. Fully open to fully closed, no in between. I rarly use the re-cir air.
So I belive this door is good.
I checked the bend doors seperatley the same way. there good aswell.
I did not check the last one yet. I wonder if it will have the fail on another drive from work to figure out the issue, Because if I use the truck later the air blows out the dash vents again.
Thanks for all the repleys but still confused why I have not figured this out yet.
DDT
Last edited:
Driving home on Friday night and a bang from the driver's side dash. The air sounded like it went from normal a/c to max (GM terms). I figured that I could live with it for awhile, but then this morning, the parts/pieces fell into the squirrel cage and all heck broke loose. I can only run fan on 3rd speed and it still has a vibration. P. I. T. A.
I emailed Heater Treater to see if I can pay more to get the parts by Friday. Pull it all and do it right.
I emailed Heater Treater to see if I can pay more to get the parts by Friday. Pull it all and do it right.
Try to narrow down the issue one step at a time. Sounds like your blend doors are fine.
Sounds like the refrigerant is low and the coils are being blocked with ice. If the AC works fine for 30 minutes then the issues start that is usually a sign of freezing. If you used the vents without the AC on and just blow outside air through them do they work for longer than 30 minutes or does the problem still exist? You can even try turning the heat on and see if the air stops blowing through the vents after 30 minutes but with 90* temps outside I am not sure I would try that one. I am trying to see if the issue is related to the AC being on specifically. If you can't reproduce this without the AC then check the refrigerant pressure.
Sounds like the refrigerant is low and the coils are being blocked with ice. If the AC works fine for 30 minutes then the issues start that is usually a sign of freezing. If you used the vents without the AC on and just blow outside air through them do they work for longer than 30 minutes or does the problem still exist? You can even try turning the heat on and see if the air stops blowing through the vents after 30 minutes but with 90* temps outside I am not sure I would try that one. I am trying to see if the issue is related to the AC being on specifically. If you can't reproduce this without the AC then check the refrigerant pressure.
When the pivot or hinge pin on the recirc door breaks on the drivers end the door can and often does fall down towards the inlet area to the fan. On mine it covered the inlet about 80-90 percent and thus very little air could get to the fan. In you case it sounds like the door might have gotten end ways as it fell and something hit the fan itself, perhaps the pivot pin which is just part of the plastic door, protruded into the fan vanes and finished breaking off and is now in the fan cage causing an inbalance or vibration. Three screws and two connectors on the fan and it is in your hand. Reach up into the cage and you will feel the loose door just layng there. It can be removed and the new one reinstalled through that fan motor hole. For now remove it so that your air will work with outside air of course because the door that closes outside air off is gone.
YOu have to remove the glove door and the panel behind it to replace the recirc door but for now you can just remove the fan motor to get the old door out of the way and get you fan looked into in case it was damaged. Probably wasn't.
YOu have to remove the glove door and the panel behind it to replace the recirc door but for now you can just remove the fan motor to get the old door out of the way and get you fan looked into in case it was damaged. Probably wasn't.
I ran my truck that way for about a year and a half. The recirc. door is the easiest to do. If you have the Infinity stereo, you will now regret that purchase, as the amplifier is blocking access to one of the screws on the door motor. If you don't, its an easy swap. Contrary to HT's instructions, their new door can be installed through the blower access, you don't have to cut the intake grille as they suggest.
Just make sure you don't overcharge the system. Your compressor will have to work harder and wear out faster. I'm a firm believer in charging it on the hottest days for that reason, and even then keeping it in the middle of the charging zone in case it gets hotter later on.
Wow, there has been some changes in methods since 2006. Our 2003 is blowing warm air again on the passenger side and its weak on air flow. Same on the floor, temp is screwd up. Recirq is very loud, air flows best in normal mode. Defrost is very weak too. System ices up in recirc mode pretty quick. The dealer fixed it twice over the years, it would be great to fix it for good. Its been broken all year, the woman of the house is sick of it... Me too, hey my 95 still blows cold air, all original too 
So, if I understand correctly, you can replace the doors without removing the dash, but that leaves out the housing and actuator replacement? Not needed? The dash pull is doable by me but, 2 hours sounds better than 8 hours labor plus the evac. .
I'm going to get the doors on ebay, the housing with the stops are not needed with these metal doors right?
Great write ups guys, thanks for posting all of this detailed info.
So, if I understand correctly, you can replace the doors without removing the dash, but that leaves out the housing and actuator replacement? Not needed? The dash pull is doable by me but, 2 hours sounds better than 8 hours labor plus the evac. .
I'm going to get the doors on ebay, the housing with the stops are not needed with these metal doors right?
Great write ups guys, thanks for posting all of this detailed info.
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Back Issues
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