As usual, you've debugged my little "problem". I had made up two inline "cooling mod harnesses" which allows me to switch them or to revert to stock completely. I was switching harnesses and it had gone on when I took off the harness that was in place. That accounts for the 5 second lapse because I disconnected the thermosensor end first, then the ECT side. It was on for 10 seconds until I plugged the other harness in on the ECT side! Duh...
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"