I have a 79 F250 with the 460 it is a camper special so it had two batteries. the drivers side positive terminal was connected to this strange looking device. you can see it has the giant red battery cable connected to it (no its not the starter solenoid that is on the passenger side by the other now main and only battery) I am trying to see if i need to run a cable to this component or if it is not needed. Anything would help thanks guys

picture is included

 

If what I am seeing is correct it looks like another solenoid. It does appear similar to a starter solenoid. I am not that familiar with camper set-ups , but it could have been used to charge a 2nd battery or maybe some other large current drawing appliance.
If has no connections to both large posts , it is probably no longer needed. If you were to trace the smaller gauge wires on the smaller terminals one should be for a ground and the other goes to whatever control/switch that activates it. The location of that wire might provide some clue what was used to activate it and why.

 

in most cases that's the solenoid for the alternator and power supply for the inside lights on the camper when it's on the truck and hooked up. but it ain't needed to start the engine or drive the truck up and down the road.