Yanmar 4jh80 oil pressure sensor

[Brick1776]

Hello I’m look for help in identifying the oil pressure sender (sensor) on my 4jh80s I’m not getting any readings for pressure at the helm. (No alarms either) the engine diagrams I have found are no help. There is one wire that has a connector labeled oil pressure so I am assuming it was never connected or the sensor was never installed. Any help would be great.

[Captain Bill]

Typically the JH series is shipped without a pressure sensor, but only a pressure switch for the idiot light. That said there is a wire for it in the wiring harness. This makes it pretty easy to add a pressure sensor. I added one to the 3JH3Es in my cat. On mine the fitting that the pressure switch was inserted into had a plugged fitting for a pressure sensor. Adding the sensor was a matter of removing the plug, screwing in the sensor, and attaching the engine side of the wire to the sensor. Of course you will need to add a compatible gauge to the instrument panel end. The oil fitting on my engines were located on the left side of the engines near the flywheel end when viewed from the front. My maintenance manual is a bit old but also covers the 4jh series and indicates the oil pressure fitting is located in the same position. I just don't know if newer 4JH engines have it in the same position.

[Brick1776]

Thank you. That explains a lot. After spending some time tinkering I believe you are right. Just a pressure switch with no sensor. I see the small screw you’re talking about to mount the sensor. Much appreciated.