Speedo stopped working

Well here's a new problem my SVX threw at me. While driving on the highway the speedo stopped working and the check engine light came on. Soon after a bearing around gear pinion had to be replaced which I'm in the process of doing now (yes I'm walking in the mean time). But oddly enough I also noticed that the fans woulod come on as soon as I turn the ignition on. How does the fan have anything to do with the speed sensor if anything at all?