Any idea what this wire is for?

[joedoh]

looks like shrink wrapped diodes in there. There are cars, like older BMW that take a positive pulse to lock and a negative pulse to unlock, so when I was installing a keyless on them I wold use just the positive lock output (that should be where that two pin plugs into, where the lock and unlock outputs are on the brain) and put diodes in just like that. Looks like a pre made harness for doing it. There are also cars with factory alarm systems that need the same setup.

The LMC keyless is probably just a generic keyless that they include with their relays and actuators to make it specific to your truck. I have a whole toolbox of stuff that "came in the box" and didnt fit the application, I say give it a chuck over the nearest shoulder.