I haven't used my bus for about 3 weeks and drove it to work today. All is
fine.

My bus is an 83.5 Watercooled 1.9 liter.

On the return trip about 1 minute into the drive the coolant light blinks,
stops then blinks again, then stopped blinking. The temp gauge hasn't even
gotten into the normal operating range at this point. The vehicle had been
running for no more than about 2 minutes total, so it wasn't even warm--let
alone overheating.

The light had stopped blinking. I pulled off the electrical connection plug
from the coolant level warning light switch in the expansion tank and the
light in the temp gauge started to blink steady and the gauge immediatly rose
to the top. The connections on the plug looked a slight bit oxidized and
maybe calcified. So I plugged and unplugged it a few times to clear some of
the oxidation, then plugged it back together. I drove the 30 minute drive
home without incident and no more blinking temp light. The temp gauge stayed
rose as the vehilce warmed to where it always does (at least for the last
year) which is a bit too much in the cool side--still slightly in the white
at the low end of the gauge spectrum.

(the low reading on the gauge might be my thermostat opening early, or open
all the time, or the temp sender--I don't know which--I've got to check it
out)

My coolant level seems fine in both expansion tanks. Is there something I
should check? Is the expansion tank cap failing? I've seen no sign of leaking
fluid.

Should the coolant level warning switch be replaced? If this coolant level
sensor is failing, could this be the cause of the low temp gauge reading or
does the temp gauge work solely off the temp gauge sender?   It seems odd
that unplugging the coolant level warning light makes the gauge rise to the
top.

Or, worse, Am I in grave danger?

I'll clean up the connections on the coolant level sensor in the daylight.

TIA
Jeff
83.5 Westy
LA,CA