Lahars are a specific kind of mudflow made up of volcanic debris. They can form in a number of situations: when small slope collapses gather water on their way down a volcano, through rapid melting of snow and ice during an eruption, from heavy rainfall on loose volcanic debris, when a volcano erupts through a crater lake, or when a crater lake drains because of overflow or wall collapse.
A relay is an electromagnetic switch operated by a relatively small electric current that can turn on or off a much larger electric current. The heart of a relay is an electromagnet (a coil of wire that becomes a temporary magnet when electricity flows through it).
A Relay Wiring Harness utilizes a 30amp fuse protected power wire that directly connects to your positive terminal on the battery. An Automotive Relay is used to pull signal from a source (Headlight connector) that triggers power to be drawn from the battery. There are two sets of cables meant to provide power to an HID ballast.