Here are some pictures of the charge wire and isolation relay as installed in my truck.
The blue wire goes back to the 7-pin connection at the back of my truck.
The red wire goes to the positive terminal on my battery with an inline 30amp fuse.
The thicker black wire is grounded to a bolt inside the engine compartment.
The thinner black wire was soldered to a blown fuse after cutting off a portion of the plastic housing, then we found a spare switched fuse slot in our fuse panel and stuck it in there.