I'm having an issue with no heat in the front. I have a 2007 Grand Caravan w/automatic dual climate control, rear heat and a/c, and a 3.8 engine. I have no heat in the front in any mode or on either side. I seem to have plenty of heat in the rear unit.

Last spring I replaced the front evaporator and heater cores. This weekend there was no heat in the front. I live in south Florida so we don't use it that much. I recalibrated the system w/o any codes. I found a bad radiator cap and also replaced the thermostat. I ran the engine until I saw flow and no air bubbles. I thought I had heat.

Tonight, no front heat. I ran the van for almost 30 min and could not really see a flow through the radiator. I did yesterday. Both heater hoses are hot. The upper radiator hose is hot, but not so hot that you can't hang on to it. My scan tool says it's running at 190 degrees.

I have recalibrated the control head several times. Since I have no heat on either side, I'm fairly sure the actuators are not the problem. I have not yet removed the actuators to visually check their operation and the blend doors. However, this unit has been screwy for a while-like heat and A/C blowing out at weird times. I recalibrated at those times, and it seemed to fix it.

I'm thinking that the control head may be bad, but can't find any information on how to test the head. Does anyone know how to test the head other than a trip to the dealership? Pull the actuators and watch the operation during a calibration cycle? Ideas?

Thanks for your help.

 

Shouldn't have to pull them, just look up above the gas pedal and there they are, see if they move. Heater hoses so hot you can't hold on?

 

Tizzy;

You may have been responding to the "no heat" thread. As I went on with the problem, I found 2 more issues. When I put in the evaporator and heater cores a while ago, I had the HVAC box on the bench and dropped a screw. I looked all over the place for that screw and especially in the gears. I couldn't find it until now. I found it lodged in the the driver's side actuator gears.

Now, I had heat the the driver's side but not the passenger side. The passenger side actuator was not working. I got no power to that actuator. I checked at the control head and again found no power to the passenger side actuator. I wasn't geting any errors. So, I replaced the control head. Everything is good now.

 

sweet, all is well that ends well!