Just installed an hour meter on my 25D with a Yanmar 1GM engine. Hot side of meter connected with red wire to the screw terminal on the end of the oil pressure sender. The voltage there, when pressure is up/engine running and ignition on is 12V positive to ground. Run a black ground wire to the bolt shaft next to the Kingston valve. The meter is mounted in a little piece of plywood with a rectangular 1" X 1.5" cutout that is screwed to the plywood bulkhead about half way to the aft of the engine. Easy to see and protected. Got the rectangular meter from West Marine. When the pressure is up, the circuit at the oil pressure sender is open and current goes thru the meter. The meter clicks every second or so and a visible rotation indicator goes around. .
jim
james.jamieson@yale.edu
Hour Meter/CD25D
Moderator: Jim Walsh