the little "curtis" hour meter gauge I put in line to monitor "on" time for the compressor so it would help me determine the next time for some grease. meter only runs when the switch is flipped on in the cab (it's also switched power so requires the key on) AND the pressure switch is open and sending power to the compressor clutch. The meter has some ability to maintain the clock internally when off and cannot be reset.

Owner caption November 2010 · Photo 846 of 1131