[Tin Foil Hat]

You didn't say what your symptom is. If you have any slack at the battery just cut 2-3 inches off and see if you have useable wire to put a new post clamp onto. If not then, while I can't say how big a job this would be, you need to remove the entire cable by working your way down it. Remember that it also goes to the starter or it's relay which is probably why your ohm meter isn't accurate.

 

[Tin Foil Hat]

Honestly, if you have a 4 year old battery that is likely the weak spot, especially if the truck can be jump started. Cold weather and extreme heat are the primary killers of batteries, or at least what exposes the weak ones.