Huh? This is the oil pressure sensor. Not related to overheating.
I found it un-nerving to drive back to the barn with the oil warning light glowing even though I knew I had ripped the sensor off like Millard did. Aside from that anxiety there is no harmful effect from running with it broken so long as you aren't losing oil there.
The replacement I got at Autozone was specified for some 20 years of Subaru models plus various Datsun, Toyota, Mazda, Mitsubishi, etc etc.
Screw or blade wire attachment is the only thing to watch for. If it looks about right and the right threads, then you've found the correct one. Yanmar used a lot of stuff also supplied to Datsun by the outside manufacturer - everything electrical, radiator cap, etc, for the Yanmars of the 70's.
