Chrysler Repair: Heater/AC dash panel buttons dont work:98 van, dodge grand caravan, fuse box

Question
Recently my wife's 1998 Dodge Grand Caravan dash button's stopped working. It's the six buttons to the left and under the two temperature slider buttons. The 3 buttons on left (which control rear wiper)don't work at all. neither do the rear window de-icer button or circ button or the A/C button? The blower switchs do work for the front and the rear. No heat either. I have checked all fuses under dash and under hood, all are good and working. Everthing worked two weeks ago and nothing has been hit or repaired. Please help! Thank you.

Answer
Hi Rick,
Sorry to be delayed in responding but our power was off for 10 hours yesterday, a bit of an electrical glitch here too.
It appears to me that the control module for the HVAC unit has either lost its power or has gone bad. There is one fuse, #6 in the fuse box under the dash, that powers it and so if you have 12v on both sides of that fuse and at pin 10 of the blue plug on the rear of the unit to which it is connected then it is getting power. Pin 21 of that same plug should be grounded as should pin 6 of the black plug.
The entire module appears to be solid state and is shown as a "black box" in the wiring diagrams so there is no way to advise you on its repair other than to look over the circuit board for any runny capacitors. All the other wires are either 'actuators' or 'drivers' that operate the various parts of the unit as based on the modules circuitry. The blowers are separate so those are unlikely to be impaired as you have observed.
So check the voltage and grounds, and look at the circuit board and if nothing seems amiss you may need to find a replacement at a wrecking yard.
Please let me know if something interesting occurs.
Roland