If that pic is of the driver side of the radiator then the connector is for your ambient temperature sensor. The sensor is missing. It is the same sensor as the one in the side of your air cleaner box. I looked for days trying to find one of these parts and finally had to go to the junk yard. I was missing the connector and the sensor.

 

Well I took it to my shop and they said it will need a new PCM. Found some used ones on Ebay for $89. Are these pretty easy to change out? Anything special I need to know. I have the Haynes manual to help me out, just wondering if anyone has had experience with this. Thanks

 

You will need a scantool to program the new pcm...

 

The Dodge DRBIII+ to be exact. Either the dealer, or certain shops, can do this.