Its a easy fix with a replacement wiring harness from CAT.
First thing after removing the valve cover is to know what wire is what.
In this case I've done pulled the wire off in question. The IVA is the round yellow thing. The one in the center is for the CAT brake.
After cutting the plug end off add the new end on as you would a light. Trim the wires back about 3/16's of a inch, slip the connector on and crimp down. Afterwards slid the heat shrink tubing over the wire and use a lighter to seal it up.
Reconnect the plug, making sure the wire do not come into contact with the cam rockers.
All together....start to finish 45min job.