Dodge Ram Climate Control

qcdodge1500 · April 2008

Hi, Well I did finally fix my problem. First off, my problem was with the AC on, and driving the air worked fine -- no problems. But when ever I slowed down to 35 or less MPH, or came to a full stop, the air coming out of the dash vents would start to blow hot. It happened every time in slowed or stopped. I would turn the AC off completly. Count to 5 or 5, 4, 3, 2, 1 and then turn it back on after I got going again. It worked fine until I touched the brakes to slow or stop,

I checked all fuses under the hoodm, and in the dash on the drivers side where the dash meets the drivers door. All were okay. I checked the vacuum lines and other vacuum related info I found on the internet. Nothing was wrong with what was recommended to check. I re-read all of the online info I could find again, and the blending door was mentioned on a few of the sites. So I checked those. Nothing was wrong and everything was working okay.

THEN I NOTICED A BLACK MOTOR TYPE HOUSING WITH A ELECTRICAL CONNECTOR UNDER THE DASH WHERE IT MEETS THE FLOOR. ALMOST EXACTLY IN THE CENTER WHERE A CONSOLE WOULD BE IF YOU HAD A SHIFTER ON THE FLOOR. IT IS ON THE PASSENGER SIDE BUT IN THE MIDDLE OF THE CONSOLE TYPE AREA. I COULD SEE WITH A FLASHLIGHT THAT THERE WAS A COLLAR OF SOMETHING TURNING CLOCKWISE AND COULD FEEL THE MOTOR TURNING IT. I SHUT OFF THE AC AND IT QUIT. THEN I TURNED THE AC ON AGAIN, AND IT STARTED TO ROTATE CLOCKWISE AS IT WAS BEFORE.

I THOUGHT WHAT THE HELL, SO I DISCONNECTED THE ELECTRICAL CONNECTOR TO THE MOTOR. THE AC STAYED ON ---- OKAY SO LETS GO FOR A TEST DRIVE AND SEE WHATS HAPPENS. DROVE FOR 7 MILES AND MAKING SURE I STOPPED MANY TIMES ALONG THE STREET (DID IT IN A RESIDENTAL AREA SO I WOULD HAVE TO STOP). THE AC STAYED ON, NEVER BLEW HOT AIR AT ALL. ---- WOW---- DID DISCONNECTING THE ELECTRIAL CONNECTOR TO THAT MOTOR WORK????? WELL IT'S BEEN 3 WEEKS AND I HAVE PUT OVER 1,000 MILES ON IT AND THE AC HAS NOT QUIT WORKING ONCE. AND BEING IN ARIZONA, THAT IS WHAT I NEEDED.

SO 3 WEEKS LATER, AC WORKS GREAT, COLD, AND AT TIME TOO COLD. THE ELECTRICAL MOTOR UNDER THE DASH AND WHERE IT MEETS THE FLOOR IN THE CENTER WHERE A CONSOLE WOULD BE CLOSEST TO THE PASSENGER SIDE DID THE TRICK FOR ME.

I hope this helps in your case. But again, if your systoms are the same as mine were, this will do the trick.. I don't know if it will affect the heater operation or not. Right now, I don't care. I'll worry about that in November.

But this is what I did to fix my problem. And I want to thank all of those who pointed me to the blending doors. It wasn't my problem, but I would have never seen the black motor that was turning whatever it was. But by disconnecting that electrical connector. All is fine.

Good luck and let me know if it works for you. If you need a picture of what I am talking about, let me know and send me your personal email address and I will take one and get it to you.

:shades: Staying cool in AZ now.

NEAR THE MIDDLE OF THE FLOOR WHERE THE TRANSMISSION IS UNDER THE TRUCK JUST WHERE THE FLOOR MEETS THE DASH IN THE MIDDLE

kp44 · May 2008

Have a 98 Dodge Ran 1500.

When I turn on the air, none will come out of the vents. it comes out through the defrost vents. It will still get cold and cool the truck down, but will not come out the right place.

How can I fix this?

thanks

kc0brn · June 2008

Same problem w/1999 Ram 1500. Tried the "pull the wires from unit under dash", while this worked, it was only temporary. Also, you have to pull the wires at just the right moment for maximum cooling. I traced the problem down to the "heat/AC controller" on the dash. I have been trying to track down the little circuit board to replace but keep hearing that I will have to replace the whole, 3 switch unit @ a trivial $150 to $200. I guess I'll have to start hitting the salvage yards...
Hope this helps those of you with the same problem.

zara3 · June 2008

Hi kc0brn;
We've been fighting to fix our climate control too in our 2002 2500.. both heat and now AC..which we had to refill to get it to work.. guess that's now leaking too...sighhhhhh

Anyway...Just wondering how you determined the problem was actually in the switch?
We got an extra switch if you want it.. Because we thought our problem was that switch too, so we bought one..put it in and...it wasn't the problem. That would have been the easy fix so we were hoping...

Our problem was the blending door (electrical) needed replacement, to fix it the Whole dash has to come out..so we finally took care of that by jury rigging the heating system last winter (kind of tricky), I wrote about it in previous posts here. But anyway, we have an extra one of those heater/AC control on the dash, it has been tested and works by the company we got it from, I could email you a picture of it if you are interested. You should be able to find them cheaper out there than those prices.

Our control unit has a vacuum switch which controls where the air goes..defrost, vent or floor. (We'll call this the directional door.) If that's the case with yours, you take out your ash tray and look on top of the heater box..you can see the actuator has a plastic hose hooked to it. That might be where your problem is..you might not be getting any vacuum..
You can test it by finding the same diameter hose and attach it to the actuator and suck on the hose to test it...you should see some movement in the little arm that sticks out.. the lever might be stuck, or the directional door itself, stuck or broken..then you got trouble if its the blending door unit.

Got to tell you...we are so disappointed in how cheap they made the Climate control in these trucks. Its a shame... And when they break.. a real pain to fix. :sick:
Good luck with it!

(I see i never did write how he jury rigged the heat to work, but he's left the room now... so that's another story)

KCRam · June 2008

Sounds like a blend door or duct issue. Unfortunately, that usually requires pulling the dash to repair.

kcram - Pickups Host

kc0brn · June 2008

Thanks zara3,
I just bought one on eBay for $47, shipping included. I'll install it as soon as it gets here and post the results. I figured it was the switch because I have checked all vacuum lines and they were all OK. I unplugged the switch and my A/C has been working ever since. Of course, I don't have any heat but don't need it this time of year, anyway. At least I didn't have to spend the $200 at the Dodge dealership, yet.... We'll see what happens.
kc0brn :confuse:

kc0brn · June 2008

Well, $#*%!!!
I guess that the switch wasn't the problem... It must be that "blending door" inside the dash, afterall. I'm not quite ready to give up and pay the dealer to fix it yet...

kc0brn :mad: :confuse:

corkscrew · June 2008

Here is a link to the tsb for replacing the blending door:
http://dodgeram.info/tsb/2002/24-004-02.htm
Hope this helps.

Regards
Corkscrew

kc0brn · June 2008

Thanks corkscrew,
I'll give that a try and post the results.

kc0brn

sinjin2 · July 2008

The blower will blow good on defrost and the floor but not the vents.

mayday5 · July 2008

My 2004 Ram 1500 A/C blower seems to work fine but no airflow from the vents. The dealer diagnosed the problem as a broken blend door in the AC housing. A $1,100 fix! Given that my vehicle has low mileage and minimal use -- it just turned 40K, the service tech. advised I contact Chrysler Customer Assistance to see if they would cover the repair. The Senior Advisor in Customer Assistance told me they would not pick up any of the expense -- the vehicle is out of warranty and the problem is not so prevalent that they feel they should pay for it. I asked for another avenue to appeal within Chrysler -- the Senior Advisor said there was none. I asked for her bosses name/number, she said she did not have one  she repeated that service issues like mine stopped with her.

If anyone knows of recourse available to me please let me know, otherwise, I will be cutting my losses with Chrysler.

myfirstdodge · July 2008

I purchased a 2004 Ram 1500 4x4 Laramie in August of 2004. As of today it turned over 39,000 miles after 4 years and had the same problem with the A/C blower working fine but with very little airflow coming from the vents.

I pulled the glove box and could see in the upper right corner of the dash that the blend door was missing. :surprise: Obviously it was broken and had fallen into the vent system. The vehicle was out of warranty last year due to the 36 month expiration but I had purchased an extended warranty because I planed on keeping the truck for many years.

The dealer replaced two doors (5073985-AA, 5073984-AA) at $87.00 for the parts but labor was $595.00. Supposedly they have to evacuate and recharge the system to do this repair. Total repair cost was $690.00 and since I had an extended warranty my part was $100.00.

I believe that extended warranties are a bad deal :P and I will have to have another major repair to break even on the cost.

Being a Dodge;

this warranty will come in handy!

mayday5 · July 2008

myfirstdodge, how ironic, my 2004 1500 Ram is a 4x4 Laramie purchased in August of 2004 also. Whats irritating is AC flow never was very strong, I just assumed low airflow was nature of this design. Then all of a sudden, airflow stopped.

Bottom line, the air conditioner failed not because I misused or abused it, it failed because the part was defective or of poor design. To expect the consumer to bear the expense in this matter speaks volumes of the company I am dealing with an automobile company I intend to stay away from in the future.

dtfamily6 · July 2008

Hello, all. Speaking of blend doors, I have a 1999 dodge ram 1500 sport where the a/c doesn't blow out at all, only hot air. I have been told this is due to the blend door not activating. It seems to be stuck on hot. My question would be is if there is any possible way to activate or close this blend door so that it's stuck on cold instead of hot, and without taking apart the entire dash? I live in Arizona where I won't need the heater to work, only the a/c. It seems like overkill to take apart the entire dash just to remove the heater box if there's a way to close the blend door manually. Any help would be appreciated.

Thank you.

kp44 · July 2008

We have a 98 Dodge 1500. The blend door quit working and would not allow any air to pass through the vents on the dash. When you turned on the a/c, it would only come out the defrost and floor.
My son figured out a way to put a piece of wood in it to make a wedge to hold the door in the correct spot

. It now works great! He will probably have to change it back this winter to get the defroster to work.

Was a cheap fix compared to the cost from the dealership.

Hope this helps you out!.

silverst1 · July 2008

I am so sick of Chrysler/Dodge making excuses for poor production and never wanting to fix the rpoblem. All they keep doing is mininmizing the situation saying that only a very few Dodge have this problem and somehow it's our problem. But they always want to know how to improve on customer service. Well rfix your damn vehicles right for starters.

baj125 · July 2008

Im having blend or vent door issues also. I was told that part wasnt covered by my extended warranty. Can you provide me with your dealer info? So i can get my dealer to talk to your dealer. Anyone else have info on warranty repairs.

myfirstdodge · July 2008

The warranty I purchased was a Master Tech Ultra Wrap Tech 2 Series whatever that means. (Im sure they sell the ones that make them the most money.) The dealer had to call the warranty company with a diagnosis to determine if it was covered or not. There is a list of about thirty items that are not covered but the A/C was not on it.

In my original reply I said that extended warranties are a bad deal and I will add to that. I will never purchase another one in the future even though it paid for my recent repair. :P

The dealer makes about sixty percent in commission from the warranty they sell you, why do you think they are so pushy. The warranty companies research the probability of what they will have to pay out and definitely have the upper hand. They would be out of business if they didnt.

hotdiggitydodg · July 2008

I'm having the same issue with my 2003 2500 Cummins Turbo Diesel. Second time. I have my truck at an independent shop and he says they are seing many of these types of repairs on good ole dodges.

His solution take the faulty "blend door" out. According to this mechanic the only downside is that it allows outside air in at all times. If I don't like it he will go back in and replace the door at about $500 labor plus parts - so not much to loose in trying.

Prior fix was at a Dodge dealership at about $650 total and 13 months ago. They refuse to re-fix under warranty since I'm outside 12 months.

fyi I have about 131,000 on this truck.

baj125 · July 2008

Thanks for the input, My extended warranty covers A/C components but not that particular part of vent system. I guess i didnt shell out for the premium package. I dont remember ever getting a choice. On the other hand i did call chrysler and had a senior customer service rep call my dealer. Due to my good loyal patronage according to the service manager, they would do the repair for $150. Thats $50 more than my warranty deductable. I was also spending About $700 for 60,000 mile service and front brakes. Sometimes it pays to be the squeeky but politly annoying wheel. We'll see what happens though if the same part breaks down again. My original estimate was around $650.
After spending a few hours on the net it seems like 90% of A/C complaints seem to be about this blend or vent door all the way back to earlier models in the late 90s. Why isnt there a class action suit out there we can bandwagon on.

hotdiggitydodg · July 2008

Got my truck back from the independent shop. They charged me $30 to remove the blend door. It's obviously broken and I'll try and post a picture of it here soon.

How it works? Just like they said. I get no change in flow when switching from recirculate to outside air but the change from floor to cabin to defrost all work. The only other issue I think is that the air on the passenger side does not feel as cold as on the drivers side but I haven't tested with a temp guage yet. I'll see if I can live with it for a while and save my money in case I have to do the full blown repair agian

I'm not a litigious person but I tend to agree if there's such a common problem Chrysler / Dodge needs to take care of their customers. If they would just cover the obvious faults in their design they would save money rather than spending it on their own defense attorneys and keep it out of the pockets of the slip and fall lawyers.

disturbedtexan · August 2008

This is discouraging... I had a 2000 RAM 1500 for six years, never a problem. I now have a 2006 RAM 1500 HEMI with the same HVAC problem as the rest of you guys. Only 25,000 miles on it, guess I'd better get to the dealer ASAP!

dtfamily6 · August 2008

My HVAC problem was actually with the hot/cold blend door which is located inside the heater box. There are other blend doors on the sides which control the venting, but this one actually mixes the hot/cold air and is controlled by the temperature dial on the dash. After extensive research and being quoted several hundred dollars in repairs from different shops, I've found that the blend door is actuated by a small motor on the bottom of the heater box, and is computer controlled. The motor is about 4x4 inches and has an electrical connector on one side and attaches to the blend door shaft in the center. There are only two small screws holding this motor in place and can be removed from the heater box from underneath the dash. One screw is a little difficult to reach because it's wedged in the corner of the transmission hump. Peeling back the carpet a bit will allow more room to get a corner screwdriver in there (I bought a $2 mini ratchet screwdriver). It turns out the motor was fried and was preventing the door from rotating. After pulling off the motor (it should pull straight down), the blend door can be rotated by hand (the shaft on the motor cannot be moved without opening up the box). There is also a small plastic connector or coupler that attaches the motor to the blend door shaft. This can sometimes crack and prevent the motor from functioning, as well. In my case, I just need to replace the motor itself. I am not sure where I might get another one aside from the dealer or a junk yard. However, I only needed the air working right now because I live in Arizona, so I pulled the top off of the motor box and calibrated it to the correct position where the blend door would be closed, closed the box, and reattached it to the blend door shaft. I only re-inserted one of the screws as there were pins on the opposite corners for the box to stay in place. The other screw (the one that's hard to get to) honestly doesn't need to be put back. Now with my blend door fixed in the cold position, I will no longer get hot air until I can replace the motor. I then had to only re-charge my freon with a can from Wal-Mart, and I was set...nice cold A/C. No dash needed to be removed and literally saved hundreds of dollars. Fixed it only with a $2 dollar screwdriver and $20 can of refrigerant from Wal-Mart. This may not be the problem with other's HVAC systems, but it's definitely worth looking into before forking out a bunch of money to those rip-off repair shops. Just remember that the dash does not need to be removed unless you actually have to remove the heater box, such as in the case of a broken blend door itself, the heater core, or the evaporater.
I hope this will be of use to at least some of you who are experience similar problems.

Thank you.

mike6295 · October 2008

Could you tell me where your son put the piece of wood? I have the exact same problem on my 2003 Ram 2500 and don't to spend the bucks right now to fix it. I do have the dash panels off now if that helps.
thanks
Mike

witchy_woman12 · October 2008

I have a 2006 Dodge Ram 2500 diesel. I had to have the water pump replaced because anti-freeze was leaking from it. Now my heater doesnt work. They told my husband to take the blend off from the fresh air return that would fix the problem, but, the only thing that did was make my truck an ice box. He put the blend door back on, but, it still doesnt work. Does anyone have any ideas. They want 600.00 dollars to rip the dash out and fix it. They said they had four more to come in with the same problem.

TCW2008 · November 2008

My heater control is not working on defrost or floor heat. Heat is Coming out the vent only. Temp control and fan speed is working fine. I had problems similar to this while it was under warranty and was told they changed the heater control panel, and that it was over $1,000.00. It worked fine after that, till last winter started doing what its doing now. Any help please.

dustyk · November 2008

It could be the control, but from what I keep hearing it could also be a Mode Door Motor (Chrysler calls the motor a "actuator"). This problem can be diagnosed using a DRB3 diagnostic tool.

Regards,
Dusty

RickD520 · January 2009

I have a problem with my air only blowing out of the defrost vent. The air will not come out on the floor or dash vents. I have placed a small block of wood on the the solenoid arm under the dash to get air to blow out of the vent. Dodge says it is the Blend Door Actuator and will cost about $750.00 to fix, I told them my block of wood works fine for now.
Any help would be greatly appreciated.

kp44 · January 2009

We use the little block of wood too. Has worked great for two years.

tpace · February 2009

I have a hvac issue with my 06 dodge ram 3500,
Fresh air seems to come in the cab and when I turn the fan speed up it vibrates bad enough to drive you out of the cab. I was trying to find some instructions online about fixing this problem myself. Any advise would be appriciated?

robbb3 · February 2009

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?

ihccgreg · February 2009

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.

ihccgreg · February 2009

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.

youtaw · March 2009

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!

corkscrew · March 2009

Here is a link to tsb 24-004-03:
http://dodgeram.info/tsb/2003/24-004-03.htm
Hope this helps

ihccgreg · March 2009

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.

seandee · March 2009

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.

arfan66 · March 2009

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......

heatertreater · March 2009

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.

HeaterTreater

arfan66 · March 2009

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!

zara3 · March 2009

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~~:)

dokkie · April 2009

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!!

heatertreater · April 2009

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.

HeaterTreater

dokkie · April 2009

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

dokkie · April 2009

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.

heatertreater · April 2009

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.

luke1633 · April 2009

2001 ram 5.9. the door only works manually,, Any ideas how to fix this cheaply??

zara3 · April 2009

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..
thanks~~~:)

heatertreater · April 2009

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.

winger1955 · April 2009

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.

Thanks

Dodge Ram Climate Control

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