Chrysler Repair: Automatic climate control: 93 LH/Concorde, automatic climate control, violet light

Question
My 1993 concode's ac stopped working and then later the heater stopped as well. I took it to a shop and they told me the Auto temp control unit was bad. I bought a new one and have the smae problem. I found from the company I bought the unit how to run a self test. The self test came back with codes 25 ( Ambient Temperature Sensor) and 26 (In-car sensor failure). At first they thought the blend door code would come back, but during the self test heat did come out of the defroster.

Do these two code indicate that two sensors are bad? If so where are they?

I assume the amibient sensor is outside somewhere and the in-car in the dash?

Answer
Hi Jeff,
You have it correctly. The ambient is outside, underneath the car mounted on the lower edge of the radiator
closure panel (actually there is a structural channel at the area below the radiator that runs transverse and the sensor is mounted on the rear surface of that channel). You can check its two wires: gray/tan goes to a pin on the 10-pin white plug of the hevac unit as well as pin 25 of the body controller bone plug, violet/light green goes to pin 10 of the gray plug of the body controller. The ambient in-car sensor is on the right side of the insturment panel behind a grille in the bezel that says chrysler or concorde on it. You remove the end cap of the dash (at the door opening) release one screw and the dash bezel can then be pryed out to give you access to the sensor and its fan. It has four wires: the gray/tan mentioned (above) which is ground wire for the sensor, red/tan which is the signal from the sensor that goes to pin 1 of the body controllers black plug, pink which is a 12v supply for the fan motor, and the yellow/dark green which when grounded caused the fan to operate which goes to pin 12 of the black plug.
So that is where those two sensors are located and their wiring. You can check the in-car sensor's fan putting tissue paper at the grille to see if it adheres to the grille as the result of the suction of the fan or not.
The sensor's resistances should change with temperature.
Roland