I just got two new locomotives (4-6-0 and 4-4-0) and have questions about the loco to tender wire bundles.  Both bundles have two pieces of loose shrink wrap(?) on them.  What is the shrink wrap for?  How do I run the wire bundles so they don't hang down and let the shrink wrap catch on switches, ties, etc.  There must be a proper way to get the wires up out of trouble and sight.

Thanks from an old newbie.  Been out of the hobby for 15 years, but getting back in with a new layout and new equipment.

Jon