Opting for Analogue not Digital
I have just finished ordering all the necessary equipment(gauges/senders/damper)to install a water temp gauge and an oil presssure gauge (both VDO)to the engine (3YM30) cockpit panel on my 2004 H33. I will retain Yanmar's water temperature alarm system and tap the additional VDO temp sender through a "T" coupling into the water-heater 5/8" inch hose. As you know, this hose runs from the base of the thermostat housing opposite the existing Yanmar temp alarm sender. There is no access/orifice on the 3YM30 to tap another sender. The local Yanmar dealer told me tapping into the water-heater hose is the best solution for the add-on temp gauge.Although the oil pressure gauge might be viewed as overkill, all my previous boats had one fitted so I feel more comfortable checking on oil pressure rather than waiting for the oil pressure alarm to sound. The 'damper' part - as Yanmar calls it, is really an adaptor that fits into the existing oil pressure entry/orifice next to the oil filter. When fitted into the engine block it provides two accesses, one for the existing alarm sender and one for the VDO oil pressure gauge sender I am about to add. Unfortunately the thread on this part (damper) is BSP rather than NPT and I could only get the appropriate VDO sender (BSP thread)as a Yanmar part, not from VDO outlets. That makes it more expensive.I thought of installing a digital water temp gauge with a pre-set temp alarm function and fitting it in place of the existing Yanmar sender. I chose not to do so because that solution might be one that would be contested by Yanmar if there is future engine overheat damage to the engine. Particularly since my engine like many others, suffered from frequent overheating when it was brand new.