Chrysler Repair: 2003 Chrysler T&C, radiator grille, overhead navigation

Question
The overhead navigation/temperautre display is reading -40 F
and the air conditioner will not cool.  If you use the auto
setting it will turn the a/c off, move the blower to the
floor and sends out hot air.  My thoughts are that it thinks
it is 40 below outside and even when set to a temp of 62
degrees it thinks it needs to be heating the air.  Can this
be reset or is it a sensor problem.

Answer
Hi April,
It could be the ambient temp sensor, the wiring from it to the front control module (located on the front edge of the power box in the engine compartment) or the display (however the fact that the heater/ac is acting up makes me believe it is not the display because the auto temp control uses the signal from the sensor for its control function).
Here the info about checking out the sensor from an earlier question I received on that subject:
The ambient temp sensor signal is off-value so much as to not make sense to the  integrated power module. That sensor is located on the front of the panel upon which the radiator sits that runs laterally across the van (or possibly to the right side of the headlamp mounting module/grille opening, behind the radiator grille but in front of the engine compartment. It has two wires that go to the front control module of the intergrated power module on the left inner fender of the engine compartment. It has two wires, violet/light greem and violet/brown that go to pin 9 and 18 of the light green/red plug at the power module. You would begin by checking the resistance across the pins of the sensor, after removing its plug. The only two reference temperature points I can give you are -40F (336 kilo-ohms) and +140F (2.49 kilo-ohms), you could interpolate between those two values for other temperatures (9-11 kilo-ohms at 68F). If the resistance seems reasonable, then I would suggest checking the continuity of the wires from the plug socket to the intergrated power module plug's pins and also check that neither is shorted to ground. I believe that the violet/brown wire should show 5V to be present when the ignition switch is in the run position.  
You could verify you have a sensor problem by getthing a fault code readout, for free at an Autozone parts store. You might well get a code P0070,0071,0072, or 0073. Those codes say the signal from the sensor is wrong and suggests that either the resistance is much higher/lower than say about 9-11 kilo-ohms at 68F or that the two wires are shorted together so that the violet/light green wire is also showing 5V or the wiring is open.
The signal is what causes the local temperature to be displayed on a readout in the cabin. My information is from the '02 manual which should apply to your '03 but I can't guarantee it.
Once you correct the sensor problem, then see if the control functions as it should.
Roland
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Thanks