QuestionQUESTION: I had the unit with a broken blend door replaced in my 2003 Caravan SE in 2013. Heater has stopped blowing hot air Monday 10/19/14. Is it possible the blend door is broken on the new unit or is there another cause for no heat. Blower motor dose work. Thanks!
ANSWER: Hi Joe,
It would first be good to see if the blend door actuator is working before thinking that the door itself has failed again. Did you replace the entire HVAC unit or simply the actuator in 2013?
You may be able to get a fault code readout with a plug-in code reader that would perhaps suggest the actuator is the issue. Or you can simply buy a new actuator and install it yourself. Is yours the system which has separate temp control for passenger side?
The other possibility is that the circulation of heated coolant is impaired, so compare the temperature that you feel on the two hoses that pass through the firewall to HVAC unit. They should feel similarly warm if the flow rate is good.
So check that out, see if you can get a fault code readout for around $40 at an independent shop, and let me know the results, or if you would like some direction as to replacing the actuator for the blend door I can tell you about that.
Please read the PS (below) and respond to it.
Thanks for doing that.
Roland
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QUESTION: Hi Roland
Thanks for your response. The entire HVAC unit was replaced(black unit with blend door and actuators). My system has only one temp control. I was a little low on coolant so I added 3/4 gallon of anti-freeze today and ran the the motor for half an hour with the heater on and temp control knob turned to the hottest setting. After running the motor for the half hour I felt the 2 hoses that go thru the firewall both were cold.
I will try and get a fault code in the next day or two. Let me know what you think of the cold hoses. Thanks
ANSWER: Hi Joe,
If it were not for the fact that the entire HVAC unit was replaced a year ago I would suspect that the heater core inside of it was blocked with debris of some sort when you find both hoses cold. But that would not happen so quickly with a new HVAC unit.
Rather I wonder if the loss of coolant that you noticed may have caused there to be an air pocket in the system which has settled inside the heater core. Getting coolant back into the entire system will probably restore the flow through the heater cored and thus both hoses being warm. But the unanswered question is why you were low about 3 quarts of anti-freeze?
Have you seen any coolant on the ground under the van where you park it?
Have you noticed when you first start the vehicle from cold that there is an unusual and prolonged amount of white smoke coming from the tail pipe? (and if so does it have the smell of anti-freeze?
Is the carpet under the HVAC unit damp?
So more observation is needed to get to the bottom of this problem. I don't believe a fault code readout of the HVAC will be helpful as this seems to be a problem with fluid loss not something electrical.
Thanks for the rating/nomination. You can do both again if this has been helpful.
Roland
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QUESTION: Hi Roland
No spots on the ground indicating a leak, no smoke from tail pipe either. The dealer I took it to for oil changes and service closed 3 yrs. ago they always topped off fluids. Where I'm going now they don't. I am going to put a new thermostat in and backwash the heater core this weekend. Is there any particular type/brand of anti-freeze required for this caravan. When I added 3 qts. of antifreeze it was prestone green AF. I'll let you know how I make out.
AnswerHi Joe,
Also check the floor under the rear cabin heater where there is another core that might be the source of your leak.
The best thing to do is stick with the same color fluid otherwise you have to flush the system to get rid of the old. Ideally the manual recommends fluids of the high organic adaptive technology or HOAT. The important thing though is not to mix fluids with different colors. I will be interested to learn what happens. Refill the radiator first, then cap that, then refill the overflow bottle to "max" and seal that. Then check the level in the overflow bottle as some more air will likely come out of the system with subsequent driving at road speed which will reduce the level in that bottle.
Thanks for the ratings and nominations which you are welcome to do both again.
Roland
