1988 GL - "Ol' Red"".

Coolant level warning light has gone ape! It blinks for a few before
startin g - then on start it goes ape! Blinks 2-3 time/sec. Then it goes
solid red - no blinking at all - just red - the it goes out completely -
a few seconds later it's back to blinking again or solid red, or it
blinks but slows to one blink every three or 4 seconds.

Coolant is up, no problem there.

Anyone got any ideas as to what this may be about? I did put in two LED
instrument lights in yesterday - but last night it didn't do this.
Tonight it's gone age!

Thanks,

John