Hi Guys, I have a 2005 Caravan with a 3.3L V-6 equipped with manual style dual controled climate control. Even though the van has been running for 15-20 minutes the heater is still blowing cold air. The coolant fluid is at proper level. The engine has reached proper operating temperature, radiator hoses are hot to the touch, A/C compressor is NOT engaged, but radiator cooling fans HAVE engaged. Air direction requests respond as desired, but there is no repsonse from the heating slider controls for both driver & passenger. Is it possible there is a break in connection from the heating control to a valve in the hot water line of the system?

Please help, I am freezing!!

Cheers!

Andy

 

how hot are the heater hoses, both should be very hot. If one is cooler than the other, it points to a plugged heater core.

Next run the hvac control head calibration test. If it passed, all the actuators are ok, the control head could still be bad.

A/C-HEATER CONTROL CALIBRATION

The A/C-heater control module must be recalibrated each time an actuator motor or the A/C-heater control is replaced. If the vehicle is so equipped, the calibration procedure also includes rear HVAC positions for each actuator motor.

1. Turn the ignition switch to the On position.
2. If equipped with the manual temperature control (MTC) system, press and hold the Rear Wipe/Wash and Recirculation buttons for at least five seconds. If equipped with the automatic temperature control (ATC) systen, simultaneously press and hold the Power and Recirculation buttons on the A/C-heater control for at least five seconds. The MTC A/C-heater control Rear Wipe/Wash button light emitting diode (LED) and Recirculation button LED, or the ATC A/C-heater control Delay and Recirculation graphics will begin to flash when the calibration procedure has begun.
3. The calibration procedure should take less than two minutes to complete for the manual A/C-heater control, and less than twenty seconds for the ATC A/C-heater control. When the LEDs or graphics stop flashing, the calibration procedure is complete.
4. If the LEDs or graphics continue to flash beyond the two minute (manual) or twenty second (ATC) calibration time, it indicates that the A/C-heater control has detected a failure and a Diagnostic Trouble Code (DTC) has been set. Refer to Body Diagnostic Procedures to perform further diagnosis. The LEDs or graphics will continue to flash even after the ignition switch is cycled Off and On, until a successful calibration is completed or until the vehicle has been driven about 13 kilometers (8 miles).

 

If there is no blockage in the heater core and everything seems to be working correctly with the heater, then check the water pump. If the pump has been replaced it is possible the impeller is slipping on the shaft.

Had this happen on my van, the impeller was plastic and it was slipping on the shaft and would move enough water to cool the engine but not enough to move it through the heater.

 

Hope its an east fix for you. It would seem if its slipping on the shaft you would see higher than normal engine temps?
FYI here is what the plastic impeller water pump autopsy revealed. Unlike you with a heater issue this left me stranded.

 

Hi guys,

Thanks to all who offered their advice, it was greatly appreciated.

I followed the steps provided from Tizzy regarding the recalibration of the heater-A/C control. Even though I had not disturbed the control face or any actuators, I performed the self-diagnostic procedure just the same. Like magic the heat is working properly. I gather like most electronics today, it must have been a glitch.

Merry Christmas & Happy New Year to all!!

Cheers!

Andy

 

HI Tizzy1,

Does this procedure work for a 2002 grand caravan with ATC?

 

Yes, the auto temp proceedure only takes about 20 seconds.

 

I would like to thank Tizzy also. I stumbled upon this post as my 06 was having the same issue. Following the instructions saved me a trip to the mechanic and $$$. Thanks!!!

 

have a 2005 Grand Caravan that blow hot air out all the time from vent just rear of right side sliding door. A/C not working either, pressures seem ok, but not cold. Probably not related, but heater thing is really annoying now that it is summer.

 

heard don't work on 2010's but could be wrong I have the manual controls.