I dont think the bp 100 could visibly tell the hours on the unit. What you may be referring to is the actual hours on the engine it may have been connected to. Plus, when the master power is on, the dash is on as well. The super dash was, however, a very reliable unit, and probably the “father” of the smartcraft gauges that Merc now has……………96 Eyra/12 Mercury 175 Pro XS with 2015 single axle trailer2017 Victory Gunner