Interceptor

The engines in my Fountain have oil temp . sending units installed in the oil cooler loop. Late last season my oil temp. gage on one engine would erratically peg to a extremely high temp. and stay there or possibly lower. Nothing else implied high oil temp. Oil looked and smelled fine, no discoloration. Engines operated fine.
The wiring at the oil temp. gage is secure so I suspect a bad sending unit. Other than swapping or replacing is there a way to troubleshhot the sending unit ?
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