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Dodge Ram Climate Control



  • Im am a new member.

    I read all 187 posts. My prob is kinda like some/most. I have an 02 1500 4.7. My issue is the heater air is cooler on driver side than pass side. Also, my defrost is cooler than use to be. I can change the direction knob and hear the doors and whatever else move. All vents work, dash floor defrost. Just not warm enough on drive side and defrost. I rem a TSB I had fixed back in 02 maybe 03 but, I was thinking it was a fan motor issue. Is there a time frame on a TSB? They worked on outside mirror too. Some clip or something.

    Any suggestions for my problem?
  • I have had this problem with my 1999 1500 Ram. After replacing the control panel in the dash only to find out it had no effect I found the problem rather easily. I borrowed a friends vacuum gauge and found out I had no vacuum pressure under the dash. I found the line feeding the HVAC system under the hood and immediately found the leak. One of the small hard plastic lines coming from the intake had a small crack in it. I spliced it with a piece of rubber vacuum line and it fixed the problem, all for about $1.00. If anyone needs a control panel for this model truck I have one I don't need. Hope this helps.
  • I used the block of wood also until I figured out I had a vacuum leak under the hood. These hard plastic lines get brittle over time and crack. I fixed my problem with a $1 vacuum hose. Hope this helps you out.
  • youtawyoutaw Posts: 1
    Just as quite a few people have posted, my dad's truck is "stuck" in vent mode only. What's weird, is that it will intermittently goto the floor, but for the most part stay on vent. We have tried calling Dodge directly and we were instructed to contact the principle owner of the dealership where my dad has a service record. The owner said he would contact a Regional Service Rep. to see if he could waive the labor cost, but that was over a month ago. A few calls later to his office and still no return phone call. (Of course as we all know now with the economy, nobody is selling vehicles, so the repair shop is where the money is coming in for them...) My dad has a friend who is a fleet division manager and he advised my dad of the TSB:24-004-03. My dad has been told that there are vacuum lines that run this function, but with a diesel, we thought this wasn't the case. We can find the vacuum line that runs the cruise control, but no others.
    Can anybody give us a direction to look to find a solution to this problem? (Other than paying the $1,000.00 FINE to Dodge for their lack of intelligence in using faulty parts and still installing them anyways..?!) Any advice will be appreciated!
  • corkscrewcorkscrew Posts: 254
    Here is a link to tsb 24-004-03:
    Hope this helps
  • ihccgregihccgreg Posts: 3
    I have only dealt with my 99 Ram 1500 gas burner. My best advice would be to continue to pursue the vacuum leak as this is most likely the problem. The line will be a very small hard plastic line that is very brittle if it is like mine. It is probably on the right side of the truck; look along the firewall to find where it enters the cab. The best way to find the leak is to take a vacuum guage and check the line starting at the engine. I also recommend checking the check valve(s) in the line, if these are malfunctioning it may not be holding enough pressure to operate the system. The system also has a vacuum resevoir but that is probably not faulty.
    Before I did anything I would take the vacuum guage and check the pressure at the door actuator under the dash, this will tell you for sure if that is the problem. If it has less than 18-20 inches of vacuum it is most likely the problem. You can splice the small hard plastic lines with the softer rubber lines available at any auto parts store. Be careful when you are searching for the leaky line and don't break or crack any others. I know this sounds like a lot but it's really not hard to do, just a process of elimination. Hope this helps.
  • seandeeseandee Posts: 2
    I am new, I hope somone can help me out.
    The other day I had three things go out at one time, my dome light does not come on when I open the drivers side door (but does when I open the pass.). The seatbelt light wont shut off when the belts are buckled and the ac blower motor does not work. Does anybody have any ideas? I hope I can get some answers befor I go to the dealership please help. Thank you . I have 2004 dodge ram 1500 3.7.
  • arfan66arfan66 Posts: 2
    You probably don't own this truck anymore but I thought I'd share what I found on mine. The blend door electrical motor gets it's position input from the temp control knob on the dash, the circuit that interprets that input is inside the small assembly case with the motor. You can do a simple function check by unscrewing the motor assembly from the bottom of the HVAC unit, next to the center console (3 screws). The inner most screw is a pain but it can be removed with a 90 deg. offset screwdriver. Mark the metal drive shaft with a sharpie. leave the electrical connector plugged in, start the truck and turn on either the A/C or heater. Rotate the temp control knob and watch the drive shaft rotate. It should move slightly at each temp knob detent. If I selected max cold or max hot, the shaft would turn nonstop in the appropriate direction. This is what broke the plastic driveshaft to blend door shaft adapter. This adapter slips off the blend door shaft and you can manually select hot or cold by turning the blend door shaft with a small pair of channel lock pliers. Now if I really wanted to fix this permanently, I'd need a new A/C - heater control panel and a new driveshaft to blend door adapter. I don't think I can find those at my local auto parts store so the manual select method will have to do. In the future, I might adapt a lawn mower throttle cable to work the blend door. Of course, I could always just buy a new truck (I'm thinking Toyota FJ).........

    Hope this helps......
  • The motor connection and shaft from the blend door axle are metal on this model. The biggest problem comes with the plastic connector between the two metal pieces. A metal replacement is available.

    The motor has internal detection circuitry for positioning the blend door and the motor can turn past the "point of no return" if it is run disconnected from the blend door. Most garages will want to replace the motor, but it can be brought back to life if you disassemble and re-index it. It's not difficult to get the system working again.

  • arfan66arfan66 Posts: 2
    Cool. I saved the motor assembly & screws. Now if I could just figure out how to re-index the motor and where to order the adapter I'd be set!

    Thanks for the insight HeaterTreater, I'll keep at it!
  • zara3zara3 Posts: 12
    Thanks, this is the info we've been looking for!
    We've resorted to installing a cable to try and control the heat over the winter, but would love to have the system working again properly~~:)
  • dokkiedokkie Posts: 8
    i have a 2001 dodge 1500 sport 4x4 with the little motor for the middle blend door i think is shot. I got kinda crazy(probably wrecked it) but i took the motor apart it was full of antifreeze from i think the heater core i replaced a few months ago. i have cleaned it and dried it outis there a certain way that these must be reset some how and should i be able to turn the shaft easily when it is sitting on the kitchen table (because i can't turn the shaft without using quite a bit of force)?? And by the way thank you all!! this is one great site i was ready to give up and go to the shop but now i'm on the road again!! ;)
  • The actuator motor assembly is a simple DC motor geared down to turn the blend doors/mode doors/and re-circ door. The motor has 360 degrees of rotation and there is no index position. Once installed, the computer controls the motor and calibrates the movement by driving the motor to the extents of movement and keeping a digital record. No matter how the motor is turned when it is removed, the computer will figure it out and calibrate correctly.

    You can check the motor with a 9V snap connector and a fresh battery. My suggestion is to cut the 9V snap connector out of your son's electric guitar and solve two problems at once...;-) The motor has two terminals and you can touch the wires to the terminal and the motor should turn and reverse when you swap the wires. If the motor is not working with the battery, you may have some luck with soaking just the motor in alcohol and drying and trying again. Nothing to lose. There are four of these motors on the truck and you can use the bad motor to lock mode door 2 in permanent 1/2floor/1/2defrost and use that motor to control the blend door. Cheap, but it will work.

    While you've got it apart you also want to check the different doors to make sure that they are operating properly. Failures on this HVAC system are common with broken control doors. The simple thing to check is the limit pin on each door. This is an extension like the tail on a "Q" that moves between stop points molded into the plenum box. This limits movement of the door and if the pin is broken, force is transferred directly to the doors and they will break. Internet searches may find more information and pictures.

  • dokkiedokkie Posts: 8
    Thank You very Much!!! I just touched a 9v battery to copper ends on the box motor turned and gears all moved freely!! I just priced one out today and they are $200 and thats with my daughters discount (shes a parts person at a dealership). Man thanks again and like I said before this is a GREAT web site with very smart people like U!! :P
  • dokkiedokkie Posts: 8
    Hi again thought my problems were over but i hooked up 9v battery and control motor works take it to truck hook it back up to wires and nothing. turning blend door(middle one controls temp) by hand and everything seems good. any ideas?? And how would i test the wire harness that hooks into the motor?? by the way i have already checked fuses and checked the wires that go to the switch it self they are plugged in properly. its still cold enough here to use heater and i can switch it to cold manually but i just hate having things not work right in my truck.
  • The computer module will run a calibration routine on the actuator motor to "learn" the end points of blend door movement and then it can regulate the position of the blend door by counting commutator clicks between the two end points. It's a cheap way to regulate a DC motor.

    The computer drives the motor to a stall point, remembers the position, then drives the other direction, counting motor revolutions by counting the clicks when the electro-magnetic polarity switches. If the door fails to stall or the distance is measured as being out of range, the computer throws a fail code and shuts the motor down until the next cal routine. If it again detects a failure, it hibernates again, shutting down the motor, and so on.

    One of two things is going on with your system.
    1. The computer got "confused" during the process of connecting/disconnecting the motor. As Bill Gates has taught us all, when you can't figure out the problem...hit the reset button. The system may just be waiting for an auto-calibration.
    2. The blend door is broken and the system will never calibrate correctly since it cannot reach a door stall point and record the extents of movement. The system will stay in an infinite loop of attempting to calibrate, failing, shutting down the motor and wait. The system will run this routine every twenty time the RAM is started.

    So...time for a reboot. If you have the fancy-schmancy Chrysler computer diagnostic tools, it's fairly simple. For the rest of us, you can force a complete system reboot by disconnecting/waiting a minute/reconnecting the main battery. The entire computer system will reboot and you may lose your radio channel program. Say hi to Bill while you're there. I think it is likely that the motor will come back to life and operate properly. We've already determined that the motor is good with the 9V battery, so the computer module is next.

    You probably should also check the limit pin on the blend door drive axle as described in the last post. If the pin is broken, it's likely that the blend door is also broken or in the process of breaking(screwing up the cal routine). Once the pin goes, it's just a matter of time until the door goes. Dodge will want to remove the plenum box to replace the door and this is an expensive repair. There are aftermarket solutions available.
  • luke1633luke1633 Posts: 3
    2001 ram 5.9. the door only works manually,, Any ideas how to fix this cheaply??
  • zara3zara3 Posts: 12
    Hi Heater Treater;
    Your information has been very helpful, we have tried resetting hoping it would auto-calibrate.. and think perhaps that little "Q" shaped bit on the door is broken, so the door goes all the way one way or the other, so its all the way on High or Off when we're are running the heat or the air-conditioning... could you tell me the aftermarket solutions available for this? Because we do not want to pull the dash apart..
  • Yes, if the limit pin is broken, the system will not calibrate and continue in a "death cycle". The door needs to be replaced to resolve the problems.

    This is a discussion only forum and links to off-site information are restricted. You are on your own searching for aftermarket solutions.
  • I purchased a 2005 Quad Cab Ram 2500 5.9 diesel with 52k. I knew when I purchased the truck that the A/C was blowing very cold but would not switch to recirculate. I figured the switch was bad but after reading this, I may have underestimated the problem. How can I troubleshoot this to determine if it is the type of problems discussed in this thread. I get very cold air but at very low velocity. It appears that all other functions work properly except recirculate. My truck does not have adjustable dual zones.

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