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Re: Gauges for Yanmar YSB-8?
A long time ago I fitted an oil pressure guage and oil pressure alarm to my old Volvo MD17C.
I put a wee T-piece in to the oil pressure port on the motor and fitted an oil pressure guage on to the bulkhead of the engine room (my engine room is open on one side so I can see the guage).
To the other side of the T-piece, I fitted the oil pressure switch again, and used it to close a relay (taken from a scrap BMW) that in turn called in a standard automobile horn (taken from another scrap automobile).
I put the horn on an engine room enable/disable switch so I don't get deafened if my head is in there during maintenance with motor stopped and ignition on. The horn is bolted to another engine room wall. It is very loud so anyone can hear it, anywhere on the boat. You need the relay as the oil pressure switch cannot carry the current for the horn.... the switch calls the horn in, but does not carry the current for the horn.
Remember to fuse the circuit for both horn and relay. The only melt-down I ever had on board was the one circuit I did not fuse on the boat.... the oil pressure switch.... and the battery just fried the cable in seconds.
With that lesson learned, it is still working, 20 years on.
The lot cost me about $30 for the (new) guage (0 to 60 psi), and about $10 for the other bits. When cold, my old motor at 2000 rpm will raise about 60 psi with new oil (15W/40 mineral), and new oil drops to about 35 psi when hot, and at the end of season to about 30 psi when hot.
Last edited by Rockter; 10-26-2014 at 10:19 AM.