1984 1.9L WBX auto trans on shakedown cruise before taking Mrs Squirrel
out camping.

This one has me puzzled.

Climbing from 2,000 ft to 5,200 ft in hot weather the coolant level lamp
started flashing. Temp gauge reading one needle width's to the right of
the lamp, radiator cooling fan running -- normal for that climb.

I got out, checked the coolant level in the expansion tank - a smidge
over "max," as the manual says it should be when warm. The v-belt was
running smoothly. Bad sensor?

Continued on my way to the top, temp gauge never going any higher, but
lamp flashing the whole way. With engine cooled, I checked the coolant
level again: right between "min" and "max."

Drove down today, mostly downhill or flat, NO flashing coolant level
lamp, engine running fine, no coolant loss.

--
Mike "Rocket J Squirrel" Elliott