whats this to and where does it connect
 

It's from 90 D150 3.9L Manual Trans. It is located under the dash on the driver's side. The wire colors are: Blue white, Yellow red, White green and Brown red.https://cimg5.ibsrv.net/gimg/dodgefo...8f63df1d34.jpg

Does everything work as it should?

Yes everything works as it does.

Probably nothing then. Maybe some accessory that yours is not equipped with.

cruise control switch connector.