Yes - I got the overheat light. It was in heavy snow and everything underneath was wet.

My sensor wiring appears to have an exposed bit of wiring due to cable sheath wear. This is likely the issue.

I will take my temp gun to measure it next time. The temp light went out immediately after I restarted the truck and the engine temp gauge had moved 0 at all during all this.

No codes are reported in the TCU - this is the newer 1999 model that has the input/output shaft sensors and more codes for transmission slip and other such malfs, so if I were slipping it would tell me.

I think I will replace the sensor. Anyone happen to know what the OBD2 PID is for the Transmission Temp?