No Heat and AC Struggles. 2001 Dodge Caravan.

[JMac101]

Hey everyone.

I have a 2001 Dodge Caravan SE 4 Cylinder 2.4 Liter.
I have No Heat at all what so ever. I flushed the heater core and it flows nicely. While hooked up the heater core hoses get hot.
In the Winter I have no heat at all, in the summer the AC works but blows hot for 3 minutes then starts to cool but barely works even though it has been recharged.
My main focus is the heat because winter is coming.
Anyone have any tips or suggestions on what to check?
Thanks in Advance.

 

[firefighter]

If your HOSES are getting hot then you probably have no air flow over the heater core. The inlet and outlet to the heater core should be differant temps, right like a radiator you will feel a differance between the inlet and outlet. That being said, Are your temp doors in your heater box moving correctly?? Do you have a ton of leaves/pine needles/garbage blocking air flow through the core(this is one of the reason for cabin filters nowadays) Or do you have enough volume, maybe waterpump going bad(impeller erroding), on a cold engine take the return line off the core and have someone start the car and you will see if you have enough volume it should push coolant out pretty good

 

[JMac101]

Yes both hoses from heater core are hot to the touch with motor running. When I flushed heater core I ran a garden hose with constant water through the top port and flowed full blast out of the bottom and then reversed the precedure and still flowed full blast. One hose is warmer then the other.
As for air flow over the heater core, that might be a possibility. As for the temp doors in my heater box moving correctly I do not know, How would I access those to check them?
I dont think the water pump is bad or going bad. The van does not overheat or leak and I take it on regular 200-300 miles trips with no issues besides no heat.

What else can I check and how do I access them temp doors in the heater box.?

 

[JMac101]

oh by the way I changed the coolant, radiator replaced and water pump replaced along with timing chain about 2 years ago, the van has 143,000 Miles, dont know if that helps.

 

[firefighter]

How long has this been a problem? since you got the van or what? You might be able to remove the blower fan and look in there with a mirror to see if the core is packed with debis(not sure all cars are differant). Does your van use a cable, electric, or vacuum motor for temp control? with the car off, but the key on with fan switched to low, air comming out of vents move your temp selector knob and see if you can hear anything moving.

 

[Chris142]

Since both heater hoses are hot you have a blend door issue. Do you know if yours are electric or run by engine vacuum?

 

[JustinH]

Sounds like a blend door problem for sure.

 

[JMac101]

Yes since I have owned the van for about 4 Years now no heat. Previous owner was a good friend of mine he told me that the heat used to work really great. When I turn the selector on I could hear a motor like a door changing positions but then I hear a snapping shut sound. Maybe the door goes half way and snaps shut or open. I dont know how or where to access the blend door. There is a part on drivers side by my feet that connects and goes through the fire wall and on the passenger side is the blower motor. Blend door is activated by small motors so yeah its electric. I have changed all of those motors as well. Is it common for blend doors to jam open or closed? Is it common for blend doors to be faulty?
Anyway for me to access this door without taking apart the entire dash bord? would the blend door most likly be on the drivers side or on the passenger side by the blower motor? heater core is located on the drivers side.

 

[JMac101]

Electric powered blend door that I know of. Has 3 small motors that control blend air temp and position of air flow. Dont know if this comes into factor, but whenever I put the air on even the AC all vents blow cool to cold but the passenger side foot compartment always blows warm and leaks condensation from the ac. I dont know if that comes into play at all why there is no heat Im just trying to include all the details. Winters coming and I dont know if I can do 10 degree weather with no heat again lol.

 

[StevieC]

Originally Posted By: JustinH
Sounds like a blend door problem for sure.
+1

 

[firefighter]

Well you have replaced the motors, remove the one for the blend door and move the linkage by hand. If you can feel it hit two stops on oppisite ends, then the door is probably in good shape. Then start the car turn on the heat, and move the door yourself and see if you get heat. If you say you can hear the door move some and then go back, either it is hitting an obstruction, or the doors might have to be callibrated with the DRBIII(chrysler factory scan tool)

 

[meep]

the scan tool calibrates the doors? my jeep has had screwed up floor/dash/defrost and cold/hot alignment issues since new... if it's a simple scan calibration it's going in to the shop. If it involves working in the dash, they aren't touching it--- took them 3 tries to install a new lock switch and 2 tries for the window switch, and still didn't get it right.

M

 

[JMac101]

ok thanks guys. I dont have the cash right now to go to the dealership for $900 and I dont know if I have enough time to attempt to remove the dash over the weekend because this van is my daily driver and I need it for work.
So the blend door is on the heater box or the heater core itself correct?
Which is behind the instrument panel on the drivers side?
That sounds like a b*tch of a job to do for one little door.
_Anyone know where I can find a diagram or print out of where the blend door is located or how to get to it online? I have been searching but I cant find a diagram for my van just other vehicles.
Thanks

 

[JMac101]

Hey Everyone Heres an update:
I dont know what wacky thing is wrong with this heater system, but I do know that I found out that the heater core does work and is not clogged.
When Thermostat (temp control) knob is turned to COLD, I get HEAT on the passsenger side foot compartment (hot heat like a blow drier). It does not matter what position the vents are turned to - When selector is on COLD I get HEAT on the passenger side foot compartment but I COLD air everywhere else.
When I turn the Thermostat (temp Control) knob to Hot I get cold air everywhere no matter what the vents are selected to and in the passenger side foot compartment I get WARM (not hot) air and everywhere else is cold.
BOTH Heater hoses are HOT Inlet and Outlet when selector is on hot, When selector is on COLD only one heater hose inlet is hot and the outlet is warm (if that matters)
All the motors for electrical control to change vent position and temperature have been changed and heater core has been flushed clear. I think if it was the heater core I wouldnt get any heat at all correct?
I have a feeling that maybe the motors for the vents or temp have been installed reversed? (For example: when turn to cold the vents go hot and vise versa)
One last thing is when I have the ac on, on a humid hot day it blows cool say about 70 degrees or a little higher but struggles and eats up my gas because it works so hard. On a cool day or decent day the AC blows cold. Either way everytime the AC is on I get a leak on the passenger side foot compartment.
When I attempt to put the heat on I do not get any leaks at all.
When I turn the car off whether it had the cold air or warm air on I get a hissing sound from the passenger side foot area.
Everything seems to lead to that point and I noticed that the passenger side air duct by the foot area used to be covered up with tape.
Im sorry I have repeated myself, but I just spent 45 minutes messing with it trying to brain storm why I do not have heat.
Good thing is, if it is just the blend door, I can reach up through the duct on the drivers side and force it open or closed. If it is the heater core, dash needs to come out.
On drivers side the motor that opens and closes the blend door, moves and turns the internals but I could hear a hiss like the door snapped off or is stripped and isnt moving but you can hear air getting around it, but If I apply pressure with my hand the hiss goes away and the air gets slightly warmer.
What gives? any takers?
Thanks guys

 

[firefighter]

Well sounds like you are on the right track. You said when it is in the cold position there is heat out of the passanger foot well, and the one heater hose is cooler then the other. That was what I was saying earlier, if one is cooler then you know you are removing heat from the core. Take the motor off for the blend(temp) door and manually move the flap and see what happens, see if you get more heat.

 

[JMac101]

I tried to remove the motor and force turn the blend door but I couldnt get it to move. I didnt want to force it too hard because I didnt want to snap it.
When I force move it should it be eay to move or stiff?
If I force the blend door open to allow heat into the cabin and I leave it forced open will it affect my ac when i try to use it?
If not I might try to force it where I need it and leave it as is and make it stay open.

 

[firefighter]

Well I think you found your problem. This is where experience comes in on knowing how much pressure to put on the door without breaking it, so I can not answer that question for you. Yes it will effect your a/c if you have it set to hot you won't have cold air. Your option now is remove the dash and the heater box, to see why the door won't move. You will have to recover the a/c refrigerant. I don't know if this is up to your skill level, I think it is a 5.5hr job. You should be able to complete it in a weekend. It would probably be nice to have heat in the winter again!!

 

[mechtech2]

Was this always this way, of only after someone worked on it?

 

[JMac101]

Hey guys heres another update::
After a few hours of messing with the heating system and the dash board, I discovered a few things.
I Removed all the motors that control the vent position hot and cold and the cabin air or fresh air. I played witht he controls to make sure all the motors worked and to identify which motor controlled what.
I discovered that the door and motor that control the cabin air and fresh air both work perfectly.
I discovered that the doors and motor that control vent position works good too.
I also removed the motor that controls the blend door and the motor works and I tried to turn the blend door manually again today and it turned. I put the air on and as I turn the door manually I could hear the door open and air rush in and as I turned it the opposite way I could hear the door close and I can hear the air flowing through the vent (i also heard the door open and when turning other way I heard it close and cut off the air flow) which is good.
As I took the screws out to remove the motor for the blend door I dropped one and it fell into this plastic cover just below it, so I decided to remove the cover. To my suprise the cover was covering the heater core and its pipes that lead through the fire wall.
Good news is either way if it is a blend door problem or heater core problem - both are located about 8 inches above my gas peddle towards the center and can be removed without disassembly of the dash.
Heres my new question:
I dont think it is the blend door because motor works and I can manually open and close it.
Both pipes in and out of heater core are hot.
Is it possible that the heater core isnt clogged and allows coolant to flow through but the heating element of the heater core is shot?
I get heat at passenger base by feet but cold everywhere else.
I guess I could shell out $150 bucks for a heater core and while Im in there I might as well replace the blend door.

 

[JMac101]

I started driving this van 4 Years ago when it was owned by a friend of mine. It never had heat that I know of in those 4 years. I was told a few years before that the heat worked great and kind of just konked out on its own.