Engine high temp indicator - false warnings?

[HighTechRedneck]

This is an 82 RTS II with a 6V92.  With the reputation, I was especially looking at operating temp and so far it appears to be ok.  Except the high engine temp warning light sometimes comes on with no apparent reason (temp is ok and coolant is at the proper level).  For example, today while warming up and getting air pressure up, the warning light came on and both the instrument panel and engine mounted coolant temp gauges read 140 degrees at the time. Sometimes it works fine.  The false alarms aren't shutting down the engine either, as they should in the event of a real overheat.

Any thoughts on the most probable cause of these false alarms?

[JackConrad]

If the High Temp warning is the same as MCI, Power goes to the warning light and from the the light it goes to ground through the hot engine sensor. It sounds like it is grounding somewhare other than the sensor. May be a chafed wire somewhere.  Hope this helps, Jack