Climate Control

The external temperature display on my 94 Park Avenue has started to display a temperature of between 145 to 150 degrees. There is no way it is that hot outside. Does anyone know what is causing this? This started last fall about a month after the AC condenser developed a leak. I have replaced the condenser and the AC works great but I can't get the external temp display to display the proper outside temp. Thanks in advance for any help.

Tony