-40 Temp & AC

Hi,
I got a 99' 323 and am having problems with my AC, it makes a loud clicking noise once I turn it on, the noise gets louder and faster once the accelerator is increased. If I leave it on with the noise, the check engine light turns on. Please tell me I don't have to replace the compressor.

Recently, my temperature reader automatically changes the temperature to -40 degrees with a bleep approximately three minutes after the engine is turned on, even if it is set to show clock or mph, temperature by the way here in Houston is about 75 degrees.
Are both of these scenerios related or are these two seprate issues?

Any opinions, comments, solutions will be appreciated.

Tyler

Unrelated. The temp problem is usually a bad connection or broken wire at the sensor. On your car the sensor should come through the lower valence panel (air dam) and is either on drivers side or passenger side this is a two wire probe connector and I have repaired a few of these by cleaning up the connection or making a new one using male/female bullet style crimp on connectors.