Hour meters are used in boats to keep track of the boat engine's run time. This is important information because most boat engines have regularly scheduled maintenance schedules, measured in engine hours. Hour meters are typically wired directly into some part of the boat that receives power only when the engine is on. This ensures that the hour meter does not run when the battery is left on or continuously. There are a variety of hour meters available in different shapes, but they function in fundamentally the same way.
Trace the outline of the recessed portion of the hour meter on the surface where you are going to mount the meter. If your hour meter is not designed to be recessed, just drill a small hole for the hour meter's wiring.
Drill out the outlined area. Use a file to make your hole the same shape as the outline.
Feed the hour meter's wires through the hole, then insert the hour meter into the hole. Secure the hour meter in place using the screws that came with the unit or screws that are appropriately sized for the unit's mounting holes.
Locate a power line that only receives power when the boat's engine is running; the wire running out of the boat's ignition to the boat's engine is ideal for this. Locate a negative wire on your boat -- this can be any wire that runs to the boat's negative battery terminal.
Place the end of one of the hour meter's wires all the way in the short channel of one of the tap-in wire connectors. Put the power line that receives power when the engine is running in the longer channel. Close the connector around the wires and squeeze it with the pliers until the locking mechanism clicks shut.
Place the end of the hour meter's other wire all the way in the short channel of the other tap-in wire connector. Put the negative wire in the longer channel. Close the connector around the wires and squeeze it with the pliers until the locking mechanism clicks shut.
Leave your boat off and check the hour meter in an hour to make sure that it hasn't changed. Turn the boat on for an hour and check it to verify that it is working.