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Dodge Ram Climate Control



  • Watch for a video showing the entire analysis and repair process to show up on youtube. Should be posted on Friday 4/24/09. The dash has a lot of plastic and screws, but it doesn't take a lot of skill to pull the glove box and center control panel to gain access to the plenum box. It will take an hour or so to fully analyze any failures, but it's just time pulling screws and pulling off panels. Once you see the tricks, it's actually very simple.

  • sk4910sk4910 Posts: 2
    The truck getting hot during idling was a bad condensor fan motor. I replaced it and that problem went away. I have checked the re-circ door and the blend door through the glove compartment hole and both of those seem to be operating properly. The popping sound has gone away so I'm guessing the system has shut down that motor. How is it possible that a single zone system can get two different temps. The dual zone system I am told has two blemd doors to separate the two zones and the single zone system has one. When I select the different flow options, i.e. floor, defrost, face, the system seems to be switching properly, but maintains the two very distinct temps. Does the single zone system have two blend doors, where the second one could be my problem?
  • Yes, the dual control has two doors and two motors. The single control is one blend door, but it's really just the same two doors connected together in the middle. Think of it like two flags on a flag pole. The connection between the two doors is very weak and it's possible for one "flag" to break off. The symptom is OK operation on the driver's side, and failure on the passenger side. The Ram has a unique blend scheme with a door above and below the heater core. The top and bottom doors move in unison to sort of "clam shell" the heater core.

    On the single control both the top and bottom set of doors have the same problem with a weak connection between the doors and if you have a broken one on either pair, you'll get strange HVAC behavior. There are aftermarket solutions for this problem, and additional pictures and video that can be found on the internet.

  • diershwdiershw Posts: 1
    2001 ram pickup 2500 10 cylinder. I get no heat by turning up the thermostat until the exact half way point. One click past half way and I get full heat. Turning the thermostat back one click turns off the heat again. The dash control panel was replaced with no change in the performance. Help please
  • Here's what I think is happening. The motor connector has a strange interface to the plastic blend door that has a tendency to slip. The forces of the actuator motor on the door are too strong and will over time either strip the motor connection or break the plastic axle receptor. When you get the slip type failure, the motor will turn to a certain point, and skip, allowing the door to fall back. Think of it like a record skipping.

    I think you are seeing the door move to a closed point, then slipping and falling back. It will only get worse. In order to diagnose the problem, you will have to get to the plenum box and remove the actuator motor and examine the axle connector. There is a video on YouTube that will give you a step by step process to get to the box, along with information on how to diagnose problems, and a repair procedure that might be of interest. Search "Dodge Ram Heater" to find the video.

  • budc130budc130 Posts: 1
    What is the name of the video thats showing on youtube about this repair on air conditioner system?
  • You can find the video by searching "Dodge Ram Heater" or my username or youtube. There are several parts, so you may have to look a little to get them in the proper sequence.
  • wes01wes01 Posts: 2
    I have a 01 2500 5.9 cummins. when in turn my AC on the passenger floor board gets soaked with water. Anyone know where it is coming from and how to stop it?
  • partsman2kpartsman2k Posts: 15
    Your drain tube it stopped up. If you get under your truck behind your right front wheel and look up you should see a plastic tube sticking down. take a water hose with a nozzle on it and spray it up into the tube to clean it out and you should be fine
  • davidlvgdavidlvg Posts: 3
    Sounds to me like you need to replace your heater core.
  • wes01wes01 Posts: 2
    thanks. ill try the water hose this afternoon.
  • thebmomthebmom Posts: 1
    Please post and let us know if that works! I have a 1996 2500 Diesel that is doing the same thing. We've been chasing that for a while now!
  • towersinktowersink Posts: 2
    my 99 ram 1500 blows hot air when its turned on. The truck has a fully charged system. what else could be wrong? :confuse:
  • I have a 2001 Dodge Ram Diesel... I charged the A/C. The Low pressure oscillates between Too Low and Too High pressure several times a minute. Stays within normal range. Should this be steady? If it should be, what could be wrong?
  • towersinktowersink Posts: 2
    If anyone can help me I posted yesterday about my 99' ram 1500 4x4 blowing hot air with a fully charged system. After looking at my truck for an hour or so I noticed that the compressor was not cycling like it should (turning off and on). Also the low pressure side gets so cold that it starts to ice over right above the compressor. Really need some help with this situation. Dont know if the compressor is bad or possibly if the pressure sensors are bad. I could really use some advice to keep repair costs down. Thnx Dave
  • I have a 2001 Dodge Ram Diesel... I charged the A/C. The Low pressure oscillates between Too Low and Too High pressure several times a minute. Stays within normal range. Should this be steady? If it should be, what could be wrong?
  • jdaggtechjdaggtech Posts: 1
    im couriese to know what youre pressures are, are you using a gauge set or just the gauge that comes with the charge cans? if you are using or can get your hands on some gauges and can give me some numbers to work with i can prob. give you a good awnser. one thing you can do real easy is look at all your a/c lines while running the a/c is there any spot that is freezing up? "trace out every line and be shure its not building up with frost anywere, if there is youre prob. is there, somthing is pluged" how mch freon did you put in it? and to awnser your question the psi may fluctuate alittle but should only be a few times a minute max. whats the ambiant temp where you are? that plays a big factor
  • mikey66mikey66 Posts: 4
    I have a 2004 ram and having problems with my a/c. The 2 vents on the driver side get cold and the 2 on the passenger side blow warm air. The controls are set to recirculate for max cooling. When I complained about this to the dealer they told me I was probably low on freon, why would it blow cold on one side and not the other?? They wouldn't acknowledge it might be a blend door. Has anybody had this problem? I'm told it's really expensive to fix it means removing the dash board to fix blend doors, of course I'm now out of warranty :mad: , Mikey66
  • mikey66mikey66 Posts: 4
    Whats the deal with these blend doors? seems to be a common problem. Thats my problem too and the dealer will not acknowledge it. Shouldn't it be some kind of recall. Maybe thats why they went bankrupt bad PR for them.
  • KCRamKCRam Mt. Arlington NJPosts: 3,516
    Check to see if your truck is covered by this TSB... if your truck is still under warranty or has an extended service plan that covers the HVAC system, your repairs should be paid for by Chrysler. Here's the TSB: TSB 24-004-03

    kcram - Pickups/Wagons Host
  • The dealer may be right with the refrigerant charge check. The RAM plenum box is built with dual 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. 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 problem, the passenger side will see it first.

    Charging the system may solve the problem and at least it should be checked, but this can be problematic if your truck is red-flagged as a "leaker". The R134a refrigerant is much less destructive than the old Freon systems, but the EPA regulations are the same. There are stringent requirements for recapture/recycle/repair of leaking refrigerant. You can get caught in government regulations that any suspected leak be repaired to stringent requirements which of course can get into big bucks in a hurry. You can buy recharge cans of R134a at any auto parts store, but it's a shot in the dark to just add refrigerant without monitoring the high and low side pressure and ambient temperature. It's worth it long term to own an AC gauge manifold and learning how to correctly evaluate and charge the system. Harbor Freight has a set that won't break the bank and you may become the most popular resident in the neighborhood with just a little learning. You may also be able to get one from the larger parts stores under their tool loan programs, but the instructions will probably be missing and you'll need to do some online learning. Of course, you need to evaluate your own conscience on doing this, and decide whether or not you will be single-handedly responsible for destroying the planet.

    If the core 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. Check the web site for diagnostic information and a video of the analysis and repair process with an aftermarket solution. The RAM system is overly complex and has multiple design weaknesses that will show up over time. Complete information and pictures are available on the web site mentioned above.

    Sorry for making this so complex, but it is! However, maintaining and repairing the system is within the capability of most DIY'ers and much much cheaper with just a little learning and effort.

  • ramhead1ramhead1 Posts: 15
    Hi.. Was hoping someone could help.. I have a 1998 Dodge Ram 1500 4x4 Regular cab 5.2 liter engine.. My air conditioning is shutting down.. It runs fine at idle speed, and blows cold air. When I run at street speed, the compressor shuts down, and the fan blows hot air. Last summer I had the evaporator core, a/c acummulator, high and low side switches replaced. At that time, the air would run for 10 minutes or so, then shut down. After a few minutes, it would come back on. Now when it shuts down, the compressor does not come back on, even at idle. I had a friend put gauges on it and the charge seems to be fine. The only thing I can think of is that it is the compressor itself, unless there is some electrical problem or switch that I do not know of.. Any help would be appreciated.. Or a link to an electrical schematic.. Thanks for any help... Keith
  • mikey66mikey66 Posts: 4
    Thanks for the reply, man it get hairy to fool with these systems. My drivers side does get really cold a lot quicker then the passengers side. It could take up to 20 min or more to cool down if at all. The fact that the driver side get really cold quicky could I still be low on feon??? Mike
  • cmoney4cmoney4 Posts: 1
    I have a 2004 Ram 2500 and am having the same issue. I sure hate to take my dash out!
  • Check the HeaterTreater video on YouTube for an overview of how to access and diagnose air flow problems without removing the dash. Repair of the system will run into big $ at the dealer, but it can be done by most DIY'ers for significantly less money and end up with a stronger system that will not fail again like just replacing the broken plastic with more plastic.
  • fourwindsfourwinds Posts: 7
    Hello...just recently started to experience minimal air flow through my dash vents, defroster, etc.., regardless of fan speed setting. I dropped the blower motor out of the case and found the recirc door had snapped off and fallen down over the blower, restricting flow. After reading some earlier posts, it sounds like this is a commom problem...I'm wondering if anyone knows about any TSB's issued for this problem? The truck is still within warranty, but it sounds like it will be easier to just buy a new door and install regards to the servo motor controlling the door, does it need to be reset somehow once the new door is installed? Thanks for your help!
  • There isn't a TSB, but the dealer can fix the problem. Their process is to remove the steering wheel/dash/evacuate AC/drain radiator/remove the plenum box and replace the door. It's a fairly involved and time consuming process and you'll end up with another plastic door that will break again plus whatever may have been screwed up in the process of disassembling and re-assembling the truck.

    HeaterTreater has a DIY kit to replace the door by just removing the glove box panel, and provides a metal replacement door that will withstand the forces in the system for the life of the RAM. Check their web site( for diagnostic information and a video showing the replacement process.

    This is a common problem with the RAM and is not confined to just the re-circ door. The RAM has four door systems for blend and airflow control and all of them are susceptible to the same fail mode as the re-circ door. While you have the dash open to replace the re-circ door, you should also check the other doors to see if there are additional problems. The two most common fails are the re-circ door and the mode 1 door(controls air distribution for vent VS floor/defrost. Full information is available at the above site.

    The actuator motor is calibrated by the computer and does not require any special alignment when installing the motor. There is a limit pin on the door axle that constrains the movement of the door between two stop points molded into the housing. The blend doors/Mode 1 door/Mode2 door all have two stop points for open/closed. However, for some unknown reason, the re-circ door only has one stop point and all force is transferred directly to the door in re-circ mode. This makes the plastic door more susceptible to failure and the design flaw is what's responsible for the failure you are seeing. While the re-circ door is a little worse with only one stop, the other doors aren't much better and over time this will be an ongoing failure issue. The doors aren't particularly hard to fix with the HeaterTreater kit, but you need to know what to look for and keep an eye on the system.
  • fourwindsfourwinds Posts: 7
    Heatertreater, thanks for the response...I just viewed the vids at your website, very informative and helpful. Extremely frustrating though to spend $$$$$ on a brand new vehicle, only to end up pulling it apart and chopping up the plenum with a dremel...since I am still within warranty, and the recirc door was relatively easy to get out, I'm going to hit the dealer up for a replacement this time around. Once I run out of warranty freebies, I guess I'll be paying you a visit for the real fix. Thanks again for the response.
  • After going through the information on the web site you probably have a better understanding of the problem and root cause than the dealership. The HeaterTreater hardware and installation method was developed for out of warranty DIY customers. However, the metal doors can be installed just like the OEM plastic when you remove the plenum box. It would be exactly the same as the dealer fix, only a reliable metal door in place of plastic.

    This is going to sound like shameless self promotion, but since you already have a little frustration with the dealer, why not mess with their minds a little. Suggest that you want warranty work done on your truck, but want HeaterTreater metal doors installed to replace all the cheap plastic and demand that they pay for the parts to make up for obvious design flaws in the system. You would end up with a long term reliable system and no cuts in the box.

    There's no way in he11 they'll go for it, but at least you can get a little satisfaction from being smarter about the Dodge Ram than they are..... In reality this would be a smart customer focused move on their part, but I wouldn't count on it.
  • ellisjay2ellisjay2 Posts: 3
    The A/C will work but doesn't blow hard enough, I've even tried closing the vents on passenger side while riding alone to send the pressure to the driver side vents but for us ram owners its obvious the air still seeps through the vents while closed. It is now hell scorching summer heat with the range of mid 90's to 100 here in atlanta GA, and after an early mourning 8hr shift its around evening hell heat time, and snow balls, + A/C+ interior = is needed. I could be wrong but I believe it blows better after driving a minute, but it seems like with this being a truck and on direct face dial, and full blast, it should be hitting me in the face little harder. Now it may take a minute but it does cool down temp wise, especially at night which is self explanitory, but after being in other smaller size vehicles with A/C blowing 10 times harder than mine, just wanted to check around and get some opinons or similar issues...then again it may be fine..but not sure...
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