QuestionQUESTION: have a 99 dodge caravan. no heat. have changed thermostat,flushed radiator,added anti-freeze,chaged heat panel. think its the heater core, found out theres two,one in front and in rear.how can i find out which one it is?
ANSWER: Hi Diane,
If could be the front heater core if you are not getting heat from the box under the dash. If the temp of the air is not warm as you would expect, start by opening the hood and locate the two rubber hoses that are routed through the upper center of the firewall to the cabin that go to the heater core inside the box under the dash. After having warmed up the engine with a drive, touch the outer surface of each of those two hoses to test whether both are about equally hot or not (they should both be hot, about the same temperature).
The rear cabin heater core if impaired would cause a lack of heat in the rear mainly.
What about the blower fan or is it mainly inadequate temperature of the air that the fan blows?
Does your control panel have separate temp controls for the driver and the passenger and if so does the passenger side get heat/the passenger side get heat/neither side gets heat.
Is the control panel conventional or does it have a digital temperature readout setting? By "changed heat panel" which panel are you speaking of, the control unit in the center stack of the dash? Is that what you replaced?
Which size engine (L) do you have? Is the temp gauge reading at leash 1/4 of full scale when you are warmed up?
Please let me know the answers to these questions.
Thanks,
Roland
---------- FOLLOW-UP ----------
QUESTION: The size motor is 3.0 when it's warmed up. The temp gauge goes where it's suppose to.there is no heat at all from either passenger side or drivers.so that means it's the front heater core out?
AnswerHi Diane,
I would believe that there may be air trapped in the system, which is why I asked you which engine. The 2.4L engine does have to have one trick done, but not the other engines.
Did you loose warmth on both areas of the van before doing anything to the system, or did this happen after you did the work on the cooling system?
How about the temp of the hoses?
That both cores are cold makes me believe the issue is trapped air in both loops of the cooling system which service the cores. What is the level of fluid in the overflow bottle? Keep adding to the max level and keep driving it more to see if the trapped air might self-remove as it is supposed to do. As the air is removed, the coolant level drops.
if that doesn't happen, and the front hoses are quite different in temp, then drain down the coolant several quarts, then disconnect the two hoses ta the fire wall and using a domestic water supply w/hose try driving water into the tubes that had the hosed connected to them...one at a time, but do it both ways to try and clear crud out of the front core.
Roland
PS: It appears then that the 2 hoses are both hot, so it isn't the core. There is either 1 or 2 "blend-air door" actuators which direct the air in varying amounts over the heater core and the AC core. That is why asked about whether you have only one or two temp choices for driver side and passenger side or not. Those are fairly easy to get to and replace yourself if necessary.
