06 grand caravan w/ manual heat 2 zone front and rear a/c heat. Some heat but not anything near what it should be. radiator is new. coolants new. Does not over heat. top rad hose is hot as is the hose feeding both rear and front heater core. Return hose off front core not as hot as the feed hose. Tried the calibration , but after 4mins the a/c led was still flashing. Turned off ignition,and turned back on with no leds flashing. Did cluster , no codes. Turned heater on ran thru allcycle modes an watched the three actuators move and all the gearing . Nothing looks stuck or broken. What else can i do,or is this a dealer fix not a DIY? Thank you.

 

A/C CONTROL HEAD RECIRCULATION PROGRAMMING

The recirculation control is programmed to cancel the recirculation mode when the ignition is turned OFF and will reset to fresh/outside air when the ignition key is turned ON. The frequent use of outside air will help keep odors from building up within the air conditioning-heater housing. It is recommended that the recirculation mode be used as little as possible, especially in humid climates. For hot and dry climates or for people who are allergic to pollens and find the frequent use of the recirculation mode necessary, the recirculation control can be reset to fresh/outside mode by the following procedure.
1.Turn the ignition key to the OFF position.
2.Turn the blower switch to any position except OFF or LOW.
3.Set the mode control to the PANEL-FACE mode.
4.Depress and hold-in the recirculation button.
5.Continue to hold-in the recirculation button, and start the engine.
6.The recirculation indicator light remains lit when the recirculation button is released. The mode will not reset when the engine is started. If the recirculation indicator light went out when the recirculation button was released, the recirculation mode reset to fresh/outside air mode when the engine is started.

The programming procedures can be repeated to change back and forth between the automatic reset and then maintain selection preference.

 

Ok. But thats not the problem. Very little heat ,slightly warm air comes out of vents. I drove it 1.75 hrs @ 80 mph no over heating . So why no hot air from vents? Thank you.

 

How many degrees difference is there? How is your coolant level? Where does your temp gauge sit at when warmed up?

 

How is the coolant Level? And if its full, have you replace the T-stat? It maybe stuck open.

 

Coolant level in full. Needle on gauge while driving at 80 mph looks like about 1/8 inch from mid gauge and a few times moved up or down a 1/16 but never reached mid gauge mark. The defrost also blows cold air . Don"t know about thermostat, dealer installed new rad. Maybe they did not change t-stat. Thank you for the reply.

 

Both of the heater hoses to the core should be very hot. You said one was cooler than the other and that usually points to a plugged heater core. Try to back flush the core with a chemical flush and see if you get improvement. The core can be replaced without removing the dash or hvac housing.

 

Ok. SO i gotta dig up the dealer invoice and see if they replaced t-stat or give them a call . If they did then i will look into back flushing the heater core. But would a plugged core create cold air in the defrost mode with temp sliders on hot? Thank you.

 

Why, does it heat in other positions? I'm going on the assumption that there is no heat in any mode. So yes, plugged heater core = no heat. Permatex makes a chemical called heavy duty radiator cleaner. Not supposed to use it on aluminum but it is the only thing I have found to clean these when they get plugged. Remove the hoses from the core and flush it separate. Only leave the chemical in for a minute or 2 or it will eat a hole right through it.

 

There is some heat in all modes except for defrost,which turns cold.