We do Fleet vehicles. None does also. Some times we will see two ports. Sometimes the wiring leaves much to be desired. But yes they will have two. Most of the time you need to go to the factory port to get a signal.
The vehicle at one time could have been a Gas company, Phone company, a Who knows company.
Life will give you rope. It will give you enough to make a ladder to pull yourself up, or an noose to hang yourself with.