He can't get the truck started yet, so doing that is a little impossible at the moment, but if the new battery gets the truck running, I would definitely agree he should have that done....

 

The "chunk" noise is probably the starter engaging but doesn't have enough power to turn the transmission. The "chatter" is the starter gear not fully engaging. Wiring is probably good since something is happening. Problem is either battery, starter, or both. Good news is that they are easy to replace.