battery cables

I have a new (newish its 3 or 4 years old) positive cable and the OE neg. The neg cable gets rather warm when I am cranking it over especially after its been sitting so long the gas drains out of the lines.
I see no problem in the line the connections are tight. It connects at the base of the battery box and again at the frame below that.
Any ideas what is causing this? The Pos cable is on a clamp style battery clamp its not one piece like some so it gets loose I have to watch it.

On another note what are the two wires that attach to the pos cable at the terminal and won't let the motor run if they are not connected?

the ground wire goes to 4 points, the battery, battery tray, the frame, and the block. All points must be clean to make a low resistance connection. A loose positive will also cause the cables to get hot due to trying to draw large amounts of current through a bad connection. The 2 wires off the positive cable supplies all the power that runs the truck - the heavy cable only goes to the starter. Also add the jumper from the last exhaust stud on the head to the firewall - it is a backup for the cab to engine and ground.

Thank You. There might be another wire grounding the block but I haven't seen it. I'll look into that. found battery cable on RA

That could be part of the issue if that frame to block cable is missing. The motor will ground through the transmission and damage the tranny if that cable is broke or missing.