I have an '04 T&C. Pretty sure 6.6.

We bought it used with very low mileage in '06.

The heat and air worked as designed until about a year ago. Then, it would cycle through Def to Face to Floor without commands. I am pretty sure the Recirculate would cycle too.

We took it to an independent garage. They said replace the controller - $600. I said No Thank You. I picked it up and guess what...it resumed working as designed on the way home from garage. So we did nothing for several months.

Then it quit working correctly and would not send air to Def. And, it seems to not get warm idling as before.

So, we buy the controller and install it. The new controller does not change the problem. So, we put in the old controller.

Now the old controller is back to working as designed.

Any suggestions appreciated.

 

The control panel IS the "BRAIN", for the entire HVAC system. Look closely at the connectors at the rear of the panel. If the unit were to lose battery voltage, it would go into "RECALIBRATE" mode when power was restored.

BTW,,,,,PRETTY SURE 6.6..????? what does that mean???

 

6.6... I am referring to engine, I think it is a 6.6 litre.

Are you saying that if it loses battery power it could have the symptoms I am reporting? If so, Could a battery or electrical system that is NOT providing adequate voltage be the issue?

Seems like this batt is old and may be a slow starter.

Thx

 

Doubt it.....If that were thhe case , you would have notivced it elsewhere, and it certainly wouldn't have lasted the "FEW MONTHS" that your problem has been occurring.

Since the problem seems to rectify itself whenever you "Fiddle" with the control head, first logical step is to look at the connections at the control head.

4 or 6 cylinder, 2.4, 3.3, or 3.8 were all that were offered. A 6.6 would be one hell of a hot-rod Minivan Though....