Weird electrical thing

Occasionally I'll get in my 2000 Limited and the truck is totally dead - no lights, no seatbelt beeper, no nothing - and of course no start. So I get out, pop the hood, touch the battery terminals, and bingo - everything's on. I cleaned the terminals and thought I had it taken care of but it happened again this morning. Could it be a grounding or cable issue, or...?

 

When ever weird stuff is happening check grounds. Absolutely.

 

I had this happen. The Negative terminal was corroded internally. The corrosion went in the cable about 8" or so. Made all kind of weird things happen. I got a negative cable tail from Autozone, used a torch, a butt connector and a ton of solder and soldered in 10" of new cable and a new terminal. No issues for years now.

 

I looked at trying to check the grounding connection and the negative cable itself; it comes off the battery, goes into a banded group of wires and the whole thing appears to head down under the engine. Any idea where it terminates? I assumed it would come off the battery to a closer or more accessible grounding point but that doesn't appear to be the case.