I would like to add a temperature gauge (at present I only have an overtemp alarm) for my Yanmar 3JH2E, which is tapped 3/8 BSPT, but have not been able to find a temperature sender in anything but NPT threads except for the $60 Yanmar part. In a 2013 thread on this forum, Maine Sail provided a reference to an oil pressure switch in BSPT that could be bought at AutoZone. Does anybody know a part number for a temperature sender that will fit this engine? Thanks.
Engine Coolant Temperature Sender
- Thread starter John Foster
- Start date
Might also try finding an adapter http://www.mcmaster.com/#bspt-to-npt-pipe-fitting-adapters/=149axz9
Saw this part specifically for yanmars that is compatible with US instruments at Catalina Parts Direct. Part #Z2998, cost $35.70. You can review the description and application at http://www.catalinadirect.com/index.cfm/product/2516/temperature-sender-yanmar-diesels.cfm
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I don't have your engine. But something to mention just in case it applies:
Are you planning to remove the temp alarm sender and replace in the same thread port with a degrees temperature sender?
My older your Yanmar model than yours has only one threaded port for a temperature sender. So I installed an automotive type degree sender by adding the appropriate female fitting onto the exterior coolant hosing that in my case feeds the output from the engine block to the thermostat. And left the temp alarm gauge sender as it was in its Yanmar designed threaded port.
I do want to be able to glance at my temp gauge periodically just to verify that the engine is running at the expected temperature. But looking at it constantly is not practical. So the temp alarm for me still is necessary to alert if the engine is overheating... which can happen between my random glances at the temp gauge.
Are you planning to remove the temp alarm sender and replace in the same thread port with a degrees temperature sender?
My older your Yanmar model than yours has only one threaded port for a temperature sender. So I installed an automotive type degree sender by adding the appropriate female fitting onto the exterior coolant hosing that in my case feeds the output from the engine block to the thermostat. And left the temp alarm gauge sender as it was in its Yanmar designed threaded port.
I do want to be able to glance at my temp gauge periodically just to verify that the engine is running at the expected temperature. But looking at it constantly is not practical. So the temp alarm for me still is necessary to alert if the engine is overheating... which can happen between my random glances at the temp gauge.
salishmermaid - thanks for the link for the adapters. They are a consideration, but I recall a post I read somewhere that mentioned the temp sender tip being left in "stagnant" water due to the length of the adapter. I don't know if that is really a problem or not.
Rardi, the 3JH2 engine has the extra port for the temp gauge sender. In fact, the wiring harness includes the wire for it as well. Thanks for your concern though.
Wiring the temperature sender is actually the easy part since the existing wiring harness has the temp gauge wire (white with black stripe) in it. The hard part is where to put the gauge. My boat has a 3rd party panel with no dedicated space for a gauge. I am considering an Actisense EMU-1 (or similar) to add engine information to my nmea2000 bus. That would allow me to have electronic gauges front and center, without affecting the existing panel, including the temperature alarm.
A less attractive (to me) alternative is a new instrument panel, although I have seen a used Yanmar panel in a local resale shop.
A less attractive (to me) alternative is a new instrument panel, although I have seen a used Yanmar panel in a local resale shop.
John, that is exactly what I did with my temp gauge sensor, and it couldn't have been easier, the NMEA 2000 compatible module plugged up to the Yanmar engine con harness and pops out temp data, RPM, batt voltage, tank levels etc to my NMEA backbone. You can pull data off where ever.
Gunni, did you use the Actisense unit or another brand (forgive me for hijacking my own thread)? And you said it "plugged up to the Yanmar engine con harness...." I expected to have to splice into the harness, either at the senders or at the panel. Were you able to actually plug in at the connector break in the harness?
Yeah, it is funny! 
I don't do my own boat electrical work so after comparing the cost to pay someone $100/hr to pull wire to my con, build a panel, and install a single gauge, the ability to send multiple engine data feeds into my network and plug it into displays looked more like a wash.
I don't do my own boat electrical work so after comparing the cost to pay someone $100/hr to pull wire to my con, build a panel, and install a single gauge, the ability to send multiple engine data feeds into my network and plug it into displays looked more like a wash.